Soft foams made from interpolymers of ethylene/alpha-olefins

ABSTRACT

Foamable compositions and soft foams comprise at least an ethylene/α-olefin interpolymer. The soft foam has a density from about 10 to 150 kg/m 3 . The foamable compositions further comprise a blowing agent. The ethylene/α-olefin interpolymers are a multi-block copolymer comprising at least one soft block and at least one hard block. Methods of making the foamable compositions and soft foams; and foam articles made from the soft foams are also described.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.60/717,893, filed Sep. 16, 2005, which further claims priority to PCTApplication No. PCT/US2005/008917, filed on Mar. 17, 2005, which in turnclaims priority to U.S. Provisional Application No. 60/553,906, filedMar. 17, 2004. For purposes of United States patent practice, thecontents of the provisional applications and the PCT application areherein incorporated by reference in their entirety.

FIELD OF THE INVENTION

This invention relates to soft foams comprising at least oneethylene/α-olefin interpolymer, and the methods of making and using thesoft foams in various applications, for example, acoustical insulation,vibration control, cushioning, specialty packaging, automotive softtouch, thermal insulation and impact absorption.

BACKGROUND OF THE INVENTION

Polyolefins such as low density polyethylene (LDPE) and polypropylene(PP) are commonly used in many non-crosslinked foam applications. Forexample, U.S. Pat. No. 6,583,193 discloses an extruded, coalescedpolypropylene foam that is either open-celled which is useful for soundinsulation applications or close celled which is useful for thermalinsulation applications. LDPE or PP can also be blended with a softercomponent such as copolymer of ethylene and vinyl acetate (EVA),ethylene-ethyl acrylate copolymer (EEA), ethylene-acrylic acid copolymer(EAA) and other ethylene copolymers having a low melting point to makesoft foams for a variety of applications. For example, U.S. Pat. No.6,590,006 discloses macrocellular foams comprising a blend of ahigh-melt-strength (HMS) polypropylene and an ethylene copolymer such asEVA, EEA, and EAA for use in sound absorption and insulationapplications.

Although there are many useful polymers and polymer blends for soft foamapplications, there are always needs for improved soft foams because ofthe continuous demands of product improvements by the consumers and foammanufacturers.

SUMMARY OF THE INVENTION

The aforementioned needs can be met by various aspects of the invention.In one aspect, the invention relates to a soft foam comprising at leastone ethylene/α-olefin interpolymer wherein the density of the foam isfrom about 10 to 150 kg/m³. In one embodiment, the ethylene/α-olefininterpolymer has a M_(w)/M_(n) from about 1.7 to about 3.5, at least onemelting point, T_(m), in degrees Celsius, and a density, d, ingrams/cubic centimeter, wherein the numerical values of T_(m) and dcorrespond to the relationship:T _(m)≧−2002.9+4538.5(d)−2422.2(d)².

In another embodiment, the ethylene/α-olefin interpolymer has aM_(w)/M_(n) from about 1.7 to about 3.5, and is characterized by a heatof fusion, ΔH in J/g, and a delta quantity, ΔT, in degrees Celsiusdefined as the temperature difference between the tallest DSC peak andthe tallest CRYSTAF peak, wherein the numerical values of ΔT and ΔH havethe following relationships:ΔT>−0.1299(ΔH)+62.81 for ΔH greater than zero and up to 130 J/g,ΔT≧48° C. for ΔH greater than 130 J/g,wherein the CRYSTAF peak is determined using at least 5 percent of thecumulative polymer, and if less than 5 percent of the polymer has anidentifiable CRYSTAF peak, then the CRYSTAF temperature is 30° C.

In another embodiment, the ethylene/α-olefin interpolymer ischaracterized by an elastic recovery, Re, in percent at 300 percentstrain and 1 cycle measured with a compression-molded film of theethylene/α-olefin interpolymer, and has a density, d, in grams/cubiccentimeter, wherein the numerical values of Re and d satisfy thefollowing relationship when the ethylene/α-olefin interpolymer issubstantially free of a cross-linked phase:Re>1481−1629(d).

In another embodiment, the ethylene/α-olefin interpolymer has amolecular fraction which elutes between 40° C. and 130° C. whenfractionated using TREF, characterized in that the fraction has a molarcomonomer content of at least 5 percent higher than that of a comparablerandom ethylene interpolymer fraction eluting between the sametemperatures, wherein said comparable random ethylene interpolymer hasthe same comonomer(s) and has a melt index, density, and molar comonomercontent (based on the whole polymer) within 10 percent of that of theethylene/α-olefin interpolymer.

In another embodiment, the ethylene/α-olefin interpolymer ischaracterized by a storage modulus at 25° C., G′(25° C.), and a storagemodulus at 100° C., G′(100° C.), wherein the ratio of G′(25° C.) toG′(100° C.) is from about 1:1 to about 10:1.

In another embodiment, the ethylene/α-olefin interpolymer has at leastone molecular fraction which elutes between 40° C. and 130° C. whenfractionated using TREF, characterized in that the fraction has a blockindex of at least 0.5 and up to about 1 and a molecular weightdistribution, M_(w)/M_(n), greater than about 1.3. In anotherembodiment, the ethylene/α-olefin interpolymer has an average blockindex greater than zero and up to about 1.0 and a molecular weightdistribution, M_(w)/M_(n), greater than about 1.3.

In another embodiment, the α-olefin in the ethylene/α-olefininterpolymer is styrene, propylene, 1-butene, 1-hexene, 1-octene,4-methyl-1-pentene, norbornene, 1-decene, 1,5-hexadiene, or acombination thereof.

In another embodiment, the soft foam disclosed herein is notcross-linked and/or contains less than 5% of gel per ASTM D-2765-84Method A. In another embodiment, the soft foam further comprising apolyolefin, which in some instances is a low density polyethylene, ahigh-melt-strength polypropylene or a combination thereof. In anotherembodiment, the ratio of the polyolefin to the ethylene/α-olefininterpolymer is from about 1:10 to about 10:1 by weight.

In another embodiment, the soft foam disclosed herein further comprisesat least an additive which, in some instances, is a grafting initiator,cross-linking catalyst, blowing agent activator, coagent, plasticizer,colorant or pigment, stability control agent, nucleating agent, filler,antioxidant, acid scavenger, ultraviolet stabilizer, flame retardant,lubricant, processing aid, extrusion aid or a combination thereof.

In another aspect, the invention relates to foamable compositionscomprising the ethylene/α-olefin interpolymer disclosed herein and ablowing agent. In one embodiment, the foamable composition furthercomprises a polyolefin. In another embodiment, the foamable compositiondoes not comprise a cross-linking agent.

In another aspect, the invention relates to foam articles made from afoam comprising the ethylene/α-olefin interpolymer disclosed herein. Inone embodiment, the foam article is suitable for acoustical insulation,vibration control, cushioning, specialty packaging, automotive softtouch, thermal insulation or impact absorption.

Additional aspects of the invention and characteristics and propertiesof various embodiments of the invention become apparent with thefollowing description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the melting point/density relationship for the inventivepolymers (represented by diamonds) as compared to traditional randomcopolymers (represented by circles) and Ziegler-Natta copolymers(represented by triangles).

FIG. 2 shows plots of delta DSC-CRYSTAF as a function of DSC MeltEnthalpy for various polymers. The diamonds represent randomethylene/octene copolymers; the squares represent polymer examples 1-4;the triangles represent polymer examples 5-9; and the circles representpolymer Examples 10-19. The “X” symbols represent polymer ComparativeExamples A*-F*.

FIG. 3 shows the effect of density on elastic recovery for unorientedfilms made from inventive interpolymers(represented by the squares andcircles) and traditional copolymers (represented by the triangles whichare various Dow AFFINITY® polymers). The squares represent inventiveethylene/butene copolymers; and the circles represent inventiveethylene/octene copolymers.

FIG. 4 is a plot of octene content of TREF fractionatedethylene/1-octene copolymer fractions versus TREF elution temperature ofthe fraction for the polymer of Example 5 (represented by the circles)and comparative polymer Comparative Examples E* and F* (represented bythe “X” symbols). The diamonds represent traditional randomethylene/octene copolymers.

FIG. 5 is a plot of octene content of TREF fractionatedethylene/1-octene copolymer fractions versus TREF elution temperature ofthe fraction for the polymer of Example 5 (curve 1) and for polymerComparative Examples F* (curve 2). The squares represent polymerComparative Examples F*; and the triangles represent Example 5.

FIG. 6 is a graph of the log of storage modulus as a function oftemperature for comparative ethylene/1-octene copolymer (curve 2) andpropylene/ethylene copolymer (curve 3) and for two ethylene/1-octeneblock copolymers of the invention made with differing quantities ofchain shuttling agent (curves 1).

FIG. 7 shows a plot of TMA (1 mm) versus flex modulus for some inventivepolymers (represented by the diamonds), as compared to some knownpolymers. The triangles represent various Dow VERSIFY® polymers; thecircles represent various random ethylene/styrene copolymers; and thesquares represent various Dow AFFINITY® polymers.

FIG. 8 shows the foam densities of Example 20 (represented by the opencircles), Example 23 (represented by the “X” symbols), Example 23P(represented by the open squares), Example 30 (represented by the opendiamonds), Example 31 (represented by the open triangles), ComparativeExample L (represented by the solid squares), and Comparative Example N(represented by the solid diamonds), as a function of foamingtemperature.

FIG. 9 shows the percentages of open cell of Example 20 (represented bythe open circles), Example 23 (represented by the “X” symbols), Example23P (represented by the open squares), Example 30 (represented by theopen diamonds), Example 31 (represented by the open triangles),Comparative Example L (represented by the solid squares), andComparative Example N (represented by the solid diamonds), as a functionof foaming temperature.

FIG. 10 shows plots of cell size versus foam density for Example 23prepared at 105° C. (represented by the open diamond), 107° C.(represented by the open circle) and 109° C. (represented by the “*”symbol) foaming temperatures respectively, Example 23P prepared at 106°C. (represented by the open square) and 108° C. (represented by the “+”symbol) foaming temperatures respectively, Example 30 prepared at 108°C. (represented by the “X” symbol) and 110° C. (represented by the opentriangle) foaming temperatures respectively, Comparative Example L(represented by the solid diamond), and Comparative Example N(represented by the solid square).

FIG. 11 shows plots of Asker C hardness versus foam density for Example23 prepared at 107° C. (represented by the open circle) and 109° C.(represented by the “*” symbol) foaming temperatures respectively,Example 23P prepared at 106° C. (represented by the open square) and108° C. (represented by the “+” symbol) foaming temperaturesrespectively, Example 30 prepared at 108° C. (represented by the “X”symbol) and 110° C. (represented by the open triangle) foamingtemperatures respectively, Comparative Example L (represented by thesolid diamond), and Comparative Example N (represented by the solidsquare).

FIG. 12 shows the vertical compression creep results of Example 23prepared at 107° C. foaming temperature, Example 23P prepared at 106° C.foaming temperature, Example 30 prepared at 108° C. foaming temperature,Comparative Example L and Comparative Example N after 1 hour, 1 day and1 week respectively.

FIG. 13 shows the vertical compression deflection results of Example 23prepared at 107° C. foaming temperature, Example 23P prepared at 106° C.foaming temperature, Example 30 prepared at 110° C. and 112° C. foamingtemperatures respectively, Comparative Example L and Comparative ExampleN at 10%, 25%, 50% and 75% deformation respectively.

FIG. 14 shows the tensile strength at break results of Example 23prepared at 107° C. (represented by the open circle) and 109° C.(represented by the “*” symbol) foaming temperatures respectively,Example 23P prepared at 106° C. (represented by the open square) and108° C. (represented by the “+” symbol) foaming temperaturesrespectively, Example 30 prepared at 108° C. (represented by the “X”symbol) and 110° C. (represented by the open triangle) foamingtemperatures respectively, Comparative Example L (represented by thesolid diamond), and Comparative Example N (represented by the solidsquare).

FIG. 15 shows the tear strength results of Example 23 prepared at 107°C. (represented by the open circle) and 109° C. (represented by the “*”symbol) foaming temperatures respectively, Example 23P prepared at 106°C. (represented by the open square) and 108° C. (represented by the “+”symbol) foaming temperatures respectively, Example 30 prepared at 108°C. (represented by the “X” symbol), 110° C. (represented by the opentriangle) and 112° C. (represented by the open diamond) foamingtemperatures respectively, Comparative Example L (represented by thesolid diamond), and Comparative Example N (represented by the solidsquare). The tear strength was normalized at 2 pounds per cubic foot(ie., 32 kg/m³) density.

FIG. 16 shows the abrasion performances of Example 23, Example 23P andExample 30 (all represented by the open squares) as well as ComparativeExample L (represented by the solid diamond) and Comparative Example M(represented by the solid triangle).

FIG. 17 shows plots of compression set and cell size for Example 23prepared at 105° C., 107° C. and 109° C. foaming temperaturesrespectively, Example 23P prepared at 106° C. and 108° C. foamingtemperatures respectively, Example 30 prepared at 108° C., 110° C. and112° C. foaming temperatures respectively, Comparative Example L, andComparative Example M.

FIG. 18 shows plots of compression set and % of open cell for Example 23prepared at 105° C., 107° C. and 109° C. foaming temperaturesrespectively, Example 23P prepared at 106° C. and 108° C. foamingtemperatures respectively, Example 30 prepared at 108° C., 110° C. and112° C. foaming temperatures respectively, Comparative Example L, andComparative Example M.

FIG. 19 shows the sound absorption performances of Example 23 preparedat 105° C. foaming temperature (represented by the open diamonds),Example 30 prepared at 112° C. foaming temperature (represented by theopen circles), Comparative Example L (represented by the solidtriangles), and Comparative Example M (represented by the solidsquares).

FIG. 20 shows the vertical compression creep results of Examples 34-35and 37-42, and Comparatives Examples Q, R, U and V at 1 hour, 1 day and1 week respectively.

FIG. 21 shows the vertical compression deflection results of Examples34-35 and 37-42, and Comparatives Examples Q, R, U and V at 25%, 50% and75% deformation respectively.

FIG. 22 shows the compression recovery results of Examples 34-35 and37-42, and Comparatives Examples Q, R, U and V at 1 hour, 1 day and 1week respectively.

FIG. 23 shows the percentages of open cell of Examples 34-35 and 37-42,and Comparatives Examples Q, R, U and V with no skin, 1 skin and 2 skinsrespectively.

FIG. 24 shows the tear strength and strain at break results of Examples34-35 and 37-42, and Comparatives Examples Q, R, U and V.

FIG. 25 shows the tensile strength and strain at break results ofExamples 34-35 and 37-42, and Comparatives Examples Q, R, U and V.

FIG. 26 shows plots of compression set and % of open cell for Examples34-35 and 37-42, and Comparatives Examples Q, R, U and V.

FIG. 27 shows plots of compression set and cell size for Examples 34-35and 37-42, and Comparatives Examples Q, R, U and V.

DETAILED DESCRIPTION OF THE INVENTION

General Definitions

“Polymer” means a polymeric compound prepared by polymerizing monomers,whether of the same or a different type. The generic term “polymer”embraces the terms “homopolymer,” “copolymer,” “terpolymer” as well as“interpolymer.”

“Interpolymer” means a polymer prepared by the polymerization of atleast two different types of monomers. The generic term “interpolymer”includes the term “copolymer” (which is usually employed to refer to apolymer prepared from two different monomers) as well as the term“terpolymer” (which is usually employed to refer to a polymer preparedfrom three different types of monomers). It also encompasses polymersmade by polymerizing four or more types of monomers.

The term “ethylene/α-olefin interpolymer” generally refers to polymerscomprising ethylene and an α-olefin having 3 or more carbon atoms.Preferably, ethylene comprises the majority mole fraction of the wholepolymer, i.e., ethylene comprises at least about 50 mole percent of thewhole polymer. More preferably ethylene comprises at least about 60 molepercent, at least about 70 mole percent, or at least about 80 molepercent, with the substantial remainder of the whole polymer comprisingat least one other comonomer that is preferably an α-olefin having 3 ormore carbon atoms. For many ethylene/octene copolymers, the preferredcomposition comprises an ethylene content greater than about 80 molepercent of the whole polymer and an octene content of from about 10 toabout 15, preferably from about 15 to about 20 mole percent of the wholepolymer. In some embodiments, the ethylene/α-olefin interpolymers do notinclude those produced in low yields or in a minor amount or as aby-product of a chemical process. While the ethylene/α-olefininterpolymers can be blended with one or more polymers, the as-producedethylene/α-olefin interpolymers are substantially pure and oftencomprise a major component of the reaction product of a polymerizationprocess.

The ethylene/α-olefin interpolymers comprise ethylene and one or morecopolymerizable α-olefin comonomers in polymerized form, characterizedby multiple blocks or segments of two or more polymerized monomer unitsdiffering in chemical or physical properties. That is, theethylene/α-olefin interpolymers are block interpolymers, preferablymulti-block interpolymers or copolymers. The terms “interpolymer” andcopolymer“are used interchangeably herein. In some embodiments, themulti-block copolymer can be represented by the following formula:(AB)_(n)where n is at least 1, preferably an integer greater than 1, such as 2,3, 4, 5, 10, 15, 20, 30, 40, 50, 60, 70, 80, 90, 100, or higher, “A”represents a hard block or segment and “B” represents a soft block orsegment. Preferably, As and Bs are linked in a substantially linearfashion, as opposed to a substantially branched or substantiallystar-shaped fashion. In other embodiments, A blocks and B blocks arerandomly distributed along the polymer chain. In other words, the blockcopolymers usually do not have a structure as follows.AAA—AA-BBB—BBIn still other embodiments, the block copolymers do not usually have athird type of block, which comprises different comonomer(s). In yetother embodiments, each of block A and block B has monomers orcomonomers substantially randomly distributed within the block. In otherwords, neither block A nor block B comprises two or more sub-segments(or sub-blocks) of distinct composition, such as a tip segment, whichhas a substantially different composition than the rest of the block.

The multi-block polymers typically comprise various amounts of “hard”and “soft” segments. “Hard” segments refer to blocks of polymerizedunits in which ethylene is present in an amount greater than about 95weight percent, and preferably greater than about 98 weight percentbased on the weight of the polymer. In other words, the comonomercontent (content of monomers other than ethylene) in the hard segmentsis less than about 5 weight percent, and preferably less than about 2weight percent based on the weight of the polymer. In some embodiments,the hard segments comprises all or substantially all ethylene. “Soft”segments, on the other hand, refer to blocks of polymerized units inwhich the comonomer content (content of monomers other than ethylene) isgreater than about 5 weight percent, preferably greater than about 8weight percent, greater than about 10 weight percent, or greater thanabout 15 weight percent based on the weight of the polymer. In someembodiments, the comonomer content in the soft segments can be greaterthan about 20 weight percent, greater than about 25 weight percent,greater than about 30 weight percent, greater than about 35 weightpercent, greater than about 40 weight percent, greater than about 45weight percent, greater than about 50 weight percent, or greater thanabout 60 weight percent.

The soft segments can often be present in a block interpolymer fromabout 1 weight percent to about 99 weight percent of the total weight ofthe block interpolymer, preferably from about 5 weight percent to about95 weight percent, from about 10 weight percent to about 90 weightpercent, from about 15 weight percent to about 85 weight percent, fromabout 20 weight percent to about 80 weight percent, from about 25 weightpercent to about 75 weight percent, from about 30 weight percent toabout 70 weight percent, from about 35 weight percent to about 65 weightpercent, from about 40 weight percent to about 60 weight percent, orfrom about 45 weight percent to about 55 weight percent of the totalweight of the block interpolymer. Conversely, the hard segments can bepresent in similar ranges. The soft segment weight percentage and thehard segment weight percentage can be calculated based on data obtainedfrom DSC or NMR. Such methods and calculations are disclosed in aconcurrently filed U.S. patent application Ser. No. 11/376,835 (insertwhen known), Attorney Docket No. 385063-999558 entitled“Ethylene/α-Olefin Block Interpolymers”, filed on Mar. 15, 2006, in thename of Colin L. P. Shan, Lonnie Hazlitt, et. al. and assigned to DowGlobal Technologies Inc., the disclose of which is incorporated byreference herein in its entirety.

The term “crystalline” if employed, refers to a polymer that possesses afirst order transition or crystalline melting point (Tm) as determinedby differential scanning calorimetry (DSC) or equivalent technique. Theterm can be used interchangeably with the term “semicrystalline”. Theterm “amorphous” refers to a polymer lacking a crystalline melting pointas determined by differential scanning calorimetry (DSC) or equivalenttechnique.

The term “multi-block copolymer” or “segmented copolymer” refers to apolymer comprising two or more chemically distinct regions or segments(referred to as “blocks”) preferably joined in a linear manner, that is,a polymer comprising chemically differentiated units which are joinedend-to-end with respect to polymerized ethylenic functionality, ratherthan in pendent or grafted fashion. In a preferred embodiment, theblocks differ in the amount or type of comonomer incorporated therein,the density, the amount of crystallinity, the crystallite sizeattributable to a polymer of such composition, the type or degree oftacticity (isotactic or syndiotactic), regio-regularity orregio-irregularity, the amount of branching, including long chainbranching or hyper-branching, the homogeneity, or any other chemical orphysical property. The multi-block copolymers are characterized byunique distributions of both polydispersity index (PDI or Mw/Mn), blocklength distribution, and/or block number distribution due to the uniqueprocess making of the copolymers. More specifically, when produced in acontinuous process, the polymers desirably possess PDI from 1.7 to 2.9,preferably from 1.8 to 2.5, more preferably from 1.8 to 2.2, and mostpreferably from 1.8 to 2.1. When produced in a batch or semi-batchprocess, the polymers possess PDI from 1.0 to 2.9, preferably from 1.3to 2.5, more preferably from 1.4 to 2.0, and most preferably from 1.4 to1.8.

In the following description, all numbers disclosed herein areapproximate values, regardless whether the word “about” or “approximate”is used in connection therewith. They may vary by 1 percent, 2 percent,5 percent, or, sometimes, 10 to 20 percent. Whenever a numerical rangewith a lower limit, R^(L) and an upper limit, R^(U), is disclosed, anynumber falling within the range is specifically disclosed. Inparticular, the following numbers within the range are specificallydisclosed: R=R^(L)+k*(R^(U)−R^(L)), wherein k is a variable ranging from1 percent to 100 percent with a 1 percent increment, i.e., k is 1percent, 2 percent, 3 percent, 4 percent, 5 percent, . . . , 50 percent,51 percent, 52 percent, . . . , 95 percent, 96 percent, 97 percent, 98percent, 99 percent, or 100 percent. Moreover, any numerical rangedefined by two R numbers as defined in the above is also specificallydisclosed.

Embodiments of the invention provide soft foams comprising at least oneethylene/α-olefin interpolymer disclosed herein wherein the foam has adensity from about 10 to 150 kg/m³. In some embodiments, theethylene/α-olefin interpolymers are a multi-block copolymer comprisingat least one soft block and at least one hard block. The soft foamsdisclosed herein can be prepared from a foamable composition comprisingat least one ethylene/α-olefin interpolymer and a blowing agent. Thesoft foams possess a well balance of desirable properties that aresuitable for a variety of applications such as acoustical insulation,vibration control, cushioning, specialty packaging, automotive softtouch, thermal insulation and impact absorption. In some embodiments,the foam contains less than 5% of gel measured according to ASTMD-2765-84 Method A. In some embodiments, the foams are cross-linked. Inother embodiments, the foams are not cross-linked.

Ethylene/α-Olefin Interpolymers

The ethylene/α-olefin interpolymers used in embodiments of the invention(also referred to as “inventive interpolymer” or “inventive polymer”)comprise ethylene and one or more copolymerizable α-olefin comonomers inpolymerized form, characterized by multiple blocks or segments of two ormore polymerized monomer units differing in chemical or physicalproperties (block interpolymer), preferably a multi-block copolymer. Theethylene/α-olefin interpolymers are characterized by one or more of theaspects described as follows.

In one aspect, the ethylene/α-olefin interpolymers used in embodimentsof the invention have a M_(w)/M_(n) from about 1.7 to about 3.5 and atleast one melting point, T_(m), in degrees Celsius and density, d, ingrams/cubic centimeter, wherein the numerical values of the variablescorrespond to the relationship:T _(m)>−2002.9+4538.5(d)−2422.2(d)², and preferablyT _(m)≧−6288.1+13141(d)−6720.3(d)², and more preferablyT _(m)≧858.91−1825.3(d)+1112.8(d)².

Such melting point/density relationship is illustrated in FIG. 1. Unlikethe traditional random copolymers of ethylene/α-olefins whose meltingpoints decrease with decreasing densities, the inventive interpolymers(represented by diamonds) exhibit melting points substantiallyindependent of the density, particularly when density is between about0.87 g/cc to about 0.95 g/cc. For example, the melting point of suchpolymers are in the range of about 110° C. to about 130° C. when densityranges from 0.875 g/cc to about 0.945 g/cc. In some embodiments, themelting point of such polymers are in the range of about 115° C. toabout 125° C. when density ranges from 0.875 g/cc to about 0.945 g/cc.

In another aspect, the ethylene/α-olefin interpolymers comprise, inpolymerized form, ethylene and one or more α-olefins and arecharacterized by a ΔT, in degree Celsius, defined as the temperature forthe tallest Differential Scanning Calorimetry (“DSC”) peak minus thetemperature for the tallest Crystallization Analysis Fractionation(“CRYSTAF”) peak and a heat of fusion in J/g, ΔH, and ΔT and ΔH satisfythe following relationships:ΔT>−0.1299(ΔH)+62.81, and preferablyΔT≧−0.1299(ΔH)+64.38, and more preferablyΔT≧−0.1299(ΔH)+65.95,for ΔH up to 130 J/g. Moreover, ΔT is equal to or greater than 48° C.for ΔH greater than 130 J/g. The CRYSTAF peak is determined using atleast 5 percent of the cumulative polymer (that is, the peak mustrepresent at least 5 percent of the cumulative polymer), and if lessthan 5 percent of the polymer has an identifiable CRYSTAF peak, then theCRYSTAF temperature is 30° C., and ΔH is the numerical value of the heatof fusion in J/g. More preferably, the highest CRYSTAF peak contains atleast 10 percent of the cumulative polymer. FIG. 2 shows plotted datafor inventive polymers as well as comparative examples. Integrated peakareas and peak temperatures are calculated by the computerized drawingprogram supplied by the instrument maker. The diagonal line shown forthe random ethylene octene comparative polymers corresponds to theequation ΔT=−0.1299 (ΔH)+62.81.

In yet another aspect, the ethylene/α-olefin interpolymers have amolecular fraction which elutes between 40° C. and 130° C. whenfractionated using Temperature Rising Elution Fractionation (“TREF”),characterized in that said fraction has a molar comonomer contenthigher, preferably at least 5 percent higher, more preferably at least10 percent higher, than that of a comparable random ethyleneinterpolymer fraction eluting between the same temperatures, wherein thecomparable random ethylene interpolymer contains the same comonomer(s),and has a melt index, density, and molar comonomer content (based on thewhole polymer) within 10 percent of that of the block interpolymer.Preferably, the M_(w)/M_(n) of the comparable interpolymer is alsowithin 10 percent of that of the block interpolymer and/or thecomparable interpolymer has a total comonomer content within 10 weightpercent of that of the block interpolymer.

In still another aspect, the ethylene/α-olefin interpolymers arecharacterized by an elastic recovery, Re, in percent at 300 percentstrain and 1 cycle measured on a compression-molded film of anethylene/α-olefin interpolymer, and has a density, d, in grams/cubiccentimeter, wherein the numerical values of Re and d satisfy thefollowing relationship when ethylene/α-olefin interpolymer issubstantially free of a cross-linked phase:Re>1481−1629(d); and preferablyRe≧1491−1629(d); and more preferablyRe>1501−1629(d); and even more preferablyRe≧1511−1629(d).

FIG. 3 shows the effect of density on elastic recovery for unorientedfilms made from certain inventive interpolymers and traditional randomcopolymers. For the same density, the inventive interpolymers havesubstantially higher elastic recoveries.

In some embodiments, the ethylene/α-olefin interpolymers have a tensilestrength above 10 MPa, preferably a tensile strength ≧11 MPa, morepreferably a tensile strength ≧13 MPa and/or an elongation at break ofat least 600 percent, more preferably at least 700 percent, highlypreferably at least 800 percent, and most highly preferably at least 900percent at a crosshead separation rate of 11 cm/minute.

In other embodiments, the ethylene/α-olefin interpolymers have (1) astorage modulus ratio, G′(25° C.)/G′(100° C.), of from 1 to 50,preferably from 1 to 20, more preferably from 1 to 10; and/or (2) a 70°C. compression set of less than 80 percent, preferably less than 70percent, especially less than 60 percent, less than 50 percent, or lessthan 40 percent, down to a compression set of 0 percent.

In still other embodiments, the ethylene/α-olefin interpolymers have a70° C. compression set of less than 80 percent, less than 70 percent,less than 60 percent, or less than 50 percent. Preferably, the 70° C.compression set of the interpolymers is less than 40 percent, less than30 percent, less than 20 percent, and may go down to about 0 percent.

In some embodiments, the ethylene/α-olefin interpolymers have a heat offusion of less than 85 J/g and/or a pellet blocking strength of equal toor less than 100 pounds/foot² (4800 Pa), preferably equal to or lessthan 50 lbs/ft² (2400 Pa), especially equal to or less than 5 lbs/ft²(240 Pa), and as low as 0 lbs/ft² (0 Pa).

In other embodiments, the ethylene/α-olefin interpolymers comprise, inpolymerized form, at least 50 mole percent ethylene and have a 70° C.compression set of less than 80 percent, preferably less than 70 percentor less than 60 percent, most preferably less than 40 to 50 percent anddown to close zero percent.

In some embodiments, the multi-block copolymers possess a PDI fitting aSchultz-Flory distribution rather than a Poisson distribution. Thecopolymers are further characterized as having both a polydisperse blockdistribution and a polydisperse distribution of block sizes andpossessing a most probable distribution of block lengths. Preferredmulti-block copolymers are those containing 4 or more blocks or segmentsincluding terminal blocks. More preferably, the copolymers include atleast 5, 10 or 20 blocks or segments including terminal blocks.

Comonomer content may be measured using any suitable technique, withtechniques based on nuclear magnetic resonance (“NMR”) spectroscopypreferred. Moreover, for polymers or blends of polymers havingrelatively broad TREF curves, the polymer desirably is firstfractionated using TREF into fractions each having an eluted temperaturerange of 10° C. or less. That is, each eluted fraction has a collectiontemperature window of 10° C. or less. Using this technique, said blockinterpolymers have at least one such fraction having a higher molarcomonomer content than a corresponding fraction of the comparableinterpolymer.

In another aspect, the inventive polymer is an olefin interpolymer,preferably comprising ethylene and one or more copolymerizablecomonomers in polymerized form, characterized by multiple blocks (i.e.,at least two blocks) or segments of two or more polymerized monomerunits differing in chemical or physical properties (blockedinterpolymer), most preferably a multi-block copolymer, said blockinterpolymer having a peak (but not just a molecular fraction) whichelutes between 40° C. and 130° C. (but without collecting and/orisolating individual fractions), characterized in that said peak, has acomonomer content estimated by infra-red spectroscopy when expandedusing a full width/half maximum (FWHM) area calculation, has an averagemolar comonomer content higher, preferably at least 5 percent higher,more preferably at least 10 percent higher, than that of a comparablerandom ethylene interpolymer peak at the same elution temperature andexpanded using a full width/half maximum (FWHM) area calculation,wherein said comparable random ethylene interpolymer has the samecomonomer(s) and has a melt index, density, and molar comonomer content(based on the whole polymer) within 10 percent of that of the blockedinterpolymer. Preferably, the M_(w)/M_(n) of the comparable interpolymeris also within 10 percent of that of the blocked interpolymer and/or thecomparable interpolymer has a total comonomer content within 10 weightpercent of that of the blocked interpolymer. The full width/half maximum(FWHM) calculation is based on the ratio of methyl to methylene responsearea [CH₃/CH₂] from the ATREF infra-red detector, wherein the tallest(highest) peak is identified from the base line, and then the FWHM areais determined. For a distribution measured using an ATREF peak, the FWHMarea is defined as the area under the curve between T₁ and T₂, where T₁and T₂ are points determined, to the left and right of the ATREF peak,by dividing the peak height by two, and then drawing a line horizontalto the base line, that intersects the left and right portions of theATREF curve. A calibration curve for comonomer content is made usingrandom ethylene/α-olefin copolymers, plotting comonomer content from NMRversus FWHM area ratio of the TREF peak. For this infra-red method, thecalibration curve is generated for the same comonomer type of interest.The comonomer content of TREF peak of the inventive polymer can bedetermined by referencing this calibration curve using its FWHMmethyl:methylene area ratio [CH₃/CH₂] of the TREF peak.

Comonomer content may be measured using any suitable technique, withtechniques based on nuclear magnetic resonance (NMR) spectroscopypreferred. Using this technique, said blocked interpolymers has highermolar comonomer content than a corresponding comparable interpolymer.

Preferably, for interpolymers of ethylene and 1-octene, the blockinterpolymer has a comonomer content of the TREF fraction elutingbetween 40 and 130° C. greater than or equal to the quantity (−0.2013)T+20.07, more preferably greater than or equal to the quantity (−0.2013)T+21.07, where T is the numerical value of the peak elution temperatureof the TREF fraction being compared, measured in ° C.

FIG. 4 graphically depicts an embodiment of the block interpolymers ofethylene and 1-octene where a plot of the comonomer content versus TREFelution temperature for several comparable ethylene/1-octeneinterpolymers (random copolymers) are fit to a line representing(−0.2013) T+20.07 (solid line). The line for the equation (−0.2013)T+21.07 is depicted by a dotted line. Also depicted are the comonomercontents for fractions of several block ethylene/1-octene interpolymersof the invention (multi-block copolymers). All of the block interpolymerfractions have significantly higher 1-octene content than either line atequivalent elution temperatures. This result is characteristic of theinventive interpolymer and is believed to be due to the presence ofdifferentiated blocks within the polymer chains, having both crystallineand amorphous nature.

FIG. 5 graphically displays the TREF curve and comonomer contents ofpolymer fractions for Example 5 and comparative F to be discussed below.The peak eluting from 40 to 130° C., preferably from 60° C. to 95° C.for both polymers is fractionated into three parts, each part elutingover a temperature range of less than 10° C. Actual data for Example 5is represented by triangles. The skilled artisan can appreciate that anappropriate calibration curve may be constructed for interpolymerscontaining different comonomers and a line used as a comparison fittedto the TREF values obtained from comparative interpolymers of the samemonomers, preferably random copolymers made using a metallocene or otherhomogeneous catalyst composition. Inventive interpolymers arecharacterized by a molar comonomer content greater than the valuedetermined from the calibration curve at the same TREF elutiontemperature, preferably at least 5 percent greater, more preferably atleast 10 percent greater.

In addition to the above aspects and properties described herein, theinventive polymers can be characterized by one or more additionalcharacteristics. In one aspect, the inventive polymer is an olefininterpolymer, preferably comprising ethylene and one or morecopolymerizable comonomers in polymerized form, characterized bymultiple blocks or segments of two or more polymerized monomer unitsdiffering in chemical or physical properties (blocked interpolymer),most preferably a multi-block copolymer, said block interpolymer havinga molecular fraction which elutes between 40° C. and 130° C., whenfractionated using TREF increments, characterized in that said fractionhas a molar comonomer content higher, preferably at least 5 percenthigher, more preferably at least 10, 15, 20 or 25 percent higher, thanthat of a comparable random ethylene interpolymer fraction elutingbetween the same temperatures, wherein said comparable random ethyleneinterpolymer comprises the same comonomer(s), preferably it is the samecomonomer(s), and a melt index, density, and molar comonomer content(based on the whole polymer) within 10 percent of that of the blockedinterpolymer. Preferably, the M_(w)/M_(n) of the comparable interpolymeris also within 10 percent of that of the blocked interpolymer and/or thecomparable interpolymer has a total comonomer content within 10 weightpercent of that of the blocked interpolymer.

Preferably, the above interpolymers are interpolymers of ethylene and atleast one α-olefin, especially those interpolymers having a wholepolymer density from about 0.855 to about 0.935 g/cm³, and moreespecially for polymers having more than about 1 mole percent comonomer,the blocked interpolymer has a comonomer content of the TREF fractioneluting between 40 and 130° C. greater than or equal to the quantity(−0.1356) T+13.89, more preferably greater than or equal to the quantity(−0.1356) T+14.93, and most preferably greater than or equal to thequantity (−0.2013)T+21.07, where T is the numerical value of the peakATREF elution temperature of the TREF fraction being compared, measuredin ° C.

Preferably, for the above interpolymers of ethylene and at least onealpha-olefin especially those interpolymers having a whole polymerdensity from about 0.855 to about 0.935 g/cm³, and more especially forpolymers having more than about 1 mole percent comonomer, the blockedinterpolymer has a comonomer content of the TREF fraction elutingbetween 40 and 130° C. greater than or equal to the quantity (−0.2013)T+20.07, more preferably greater than or equal to the quantity (−0.2013)T+21.07, where T is the numerical value of the peak elution temperatureof the TREF fraction being compared, measured in ° C.

In still another aspect, the inventive polymer is an olefininterpolymer, preferably comprising ethylene and one or morecopolymerizable comonomers in polymerized form, characterized bymultiple blocks or segments of two or more polymerized monomer unitsdiffering in chemical or physical properties (blocked interpolymer),most preferably a multi-block copolymer, said block interpolymer havinga molecular fraction which elutes between 40° C. and 130° C., whenfractionated using TREF increments, characterized in that every fractionhaving a comonomer content of at least about 6 mole percent, has amelting point greater than about 100° C. For those fractions having acomonomer content from about 3 mole percent to about 6 mole percent,every fraction has a DSC melting point of about 110° C. or higher. Morepreferably, said polymer fractions, having at least 1 mol percentcomonomer, has a DSC melting point that corresponds to the equation:T _(m)≧(−5.5926)(mol percent comonomer in the fraction)+135.90.

In yet another aspect, the inventive polymer is an olefin interpolymer,preferably comprising ethylene and one or more copolymerizablecomonomers in polymerized form, characterized by multiple blocks orsegments of two or more polymerized monomer units differing in chemicalor physical properties (blocked interpolymer), most preferably amulti-block copolymer, said block interpolymer having a molecularfraction which elutes between 40° C. and 130° C., when fractionatedusing TREF increments, characterized in that every fraction that has anATREF elution temperature greater than or equal to about 76° C., has amelt enthalpy (heat of fusion) as measured by DSC, corresponding to theequation:Heat of fusion (J/gm)≦(3.1718)(ATREF elution temperature inCelsius)−136.58,

The inventive block interpolymers have a molecular fraction which elutesbetween 40° C. and 130° C., when fractionated using TREF increments,characterized in that every fraction that has an ATREF elutiontemperature between 40° C. and less than about 76° C., has a meltenthalpy (heat of fusion) as measured by DSC, corresponding to theequation:Heat of fusion (J/gm)≦(1.1312)(ATREF elution temperature inCelsius)+22.97.ATREF Peak Comonomer Composition Measurement by Infra-Red Detector

The comonomer composition of the TREF peak can be measured using an IR4infra-red detector available from Polymer Char, Valencia, Spain(http://www.polymerchar.com/).

The “composition mode” of the detector is equipped with a measurementsensor (CH₂) and composition sensor (CH₃) that are fixed narrow bandinfra-red filters in the region of 2800-3000 cm⁻¹. The measurementsensor detects the methylene (CH₂) carbons on the polymer (whichdirectly relates to the polymer concentration in solution) while thecomposition sensor detects the methyl (CH₃) groups of the polymer. Themathematical ratio of the composition signal (CH₃) divided by themeasurement signal (CH₂) is sensitive to the comonomer content of themeasured polymer in solution and its response is calibrated with knownethylene alpha-olefin copolymer standards.

The detector when used with an ATREF instrument provides both aconcentration (CH₂) and composition (CH₃) signal response of the elutedpolymer during the TREF process. A polymer specific calibration can becreated by measuring the area ratio of the CH₃ to CH₂ for polymers withknown comonomer content (preferably measured by NMR). The comonomercontent of an ATREF peak of a polymer can be estimated by applying a thereference calibration of the ratio of the areas for the individual CH₃and CH₂ response (i.e. area ratio CH₃/CH₂ versus comonomer content).

The area of the peaks can be calculated using a full width/half maximum(FWHM) calculation after applying the appropriate baselines to integratethe individual signal responses from the TREF chromatogram. The fullwidth/half maximum calculation is based on the ratio of methyl tomethylene response area [CH₃/CH₂] from the ATREF infra-red detector,wherein the tallest (highest) peak is identified from the base line, andthen the FWHM area is determined. For a distribution measured using anATREF peak, the FWHM area is defined as the area under the curve betweenT1 and T2, where T1 and T2 are points determined, to the left and rightof the ATREF peak, by dividing the peak height by two, and then drawinga line horizontal to the base line, that intersects the left and rightportions of the ATREF curve.

The application of infra-red spectroscopy to measure the comonomercontent of polymers in this ATREF-infra-red method is, in principle,similar to that of GPC/FTIR systems as described in the followingreferences: Markovich, Ronald P.; Hazlitt, Lonnie G.; Smith, Linley;“Development of gel-permeation chromatography-Fourier transform infraredspectroscopy for characterization of ethylene-based polyolefincopolymers”. Polymeric Materials Science and Engineering (1991), 65,98-100. ; and Deslauriers, P. J.; Rohlfing, D. C.; Shieh, E. T.;“Quantifying short chain branching microstructures in ethylene-1-olefincopolymers using size exclusion chromatography and Fourier transforminfrared spectroscopy (SEC-FTIR)”, Polymer (2002), 43, 59-170, both ofwhich are incorporated by reference herein in their entirety.

In other embodiments, the inventive ethylene/α-olefin interpolymer ischaracterized by an average block index, ABI, which is greater than zeroand up to about 1.0 and a molecular weight distribution, M_(w)/M_(n),greater than about 1.3. The average block index, ABI, is the weightaverage of the block index (“BI”) for each of the polymer fractionsobtained in preparative TREF from 20° C. and 110° C., with an incrementof 5° C.:ABI=Σ(w _(i) BI _(i))

where BI_(i) is the block index for the ith fraction of the inventiveethylene/α-olefin interpolymer obtained in preparative TREF, and w_(i)is the weight percentage of the ith fraction.

For each polymer fraction, BI is defined by one of the two followingequations (both of which give the same BI value):

${BI} = {{\frac{{1/T_{X}} - {1/T_{XO}}}{{1/T_{A}} - {1/T_{AB}}}\mspace{14mu}{or}\mspace{14mu}{BI}} = {- \frac{{{Ln}\; P_{X}} - {{Ln}\; P_{XO}}}{{{Ln}\; P_{A}} - {{Ln}\; P_{AB}}}}}$

where T_(X) is the preparative ATREF elution temperature for the ithfraction (preferably expressed in Kelvin), P_(X) is the ethylene molefraction for the ith fraction, which can be measured by NMR or IR asdescribed above. P_(AB) is the ethylene mole fraction of the wholeethylene/α-olefin interpolymer (before fractionation), which also can bemeasured by NMR or IR. T_(A) and P_(A) are the ATREF elution temperatureand the ethylene mole fraction for pure “hard segments” (which refer tothe crystalline segments of the interpolymer). As a first orderapproximation, the T_(A) and P_(A) values are set to those for highdensity polyethylene homopolymer, if the actual values for the “hardsegments” are not available. For calculations performed herein, T_(A) is372° K, P_(A) is 1.

T_(AB) is the ATREF temperature for a random copolymer of the samecomposition and having an ethylene mole fraction of P_(AB). T_(AB) canbe calculated from the following equation:Ln P _(AB) =α/T _(AB)+βwhere α and β are two constants which can be determined by calibrationusing a number of known random ethylene copolymers. It should be notedthat α and β may vary from instrument to instrument. Moreover, one wouldneed to create their own calibration curve with the polymer compositionof interest and also in a similar molecular weight range as thefractions. There is a slight molecular weight effect. If the calibrationcurve is obtained from similar molecular weight ranges, such effectwould be essentially negligible. In some embodiments, random ethylenecopolymers satisfy the following relationship:Ln P=−237.83/T _(ATREF)+0.639

T_(XO) is the ATREF temperature for a random copolymer of the samecomposition and having an ethylene mole fraction of P_(X). T_(XO) can becalculated from LnP_(X)=α/T_(XO)+β. Conversely, P_(XO) is the ethylenemole fraction for a random copolymer of the same composition and havingan ATREF temperature of T_(X), which can be calculated from LnP_(XO)=α/T_(X)+β.

Once the block index (BI) for each preparative TREF fraction isobtained, the weight average block index, ABI, for the whole polymer canbe calculated. In some embodiments, ABI is greater than zero but lessthan about 0.3 or from about 0.1 to about 0.3. In other embodiments, ABIis greater than about 0.3 and up to about 1.0. Preferably, ABI should bein the range of from about 0.4 to about 0.7, from about 0.5 to about0.7, or from about 0.6 to about 0.9. In some embodiments, ABI is in therange of from about 0.3 to about 0.9, from about 0.3 to about 0.8, orfrom about 0.3 to about 0.7, from about 0.3 to about 0.6, from about 0.3to about 0.5, or from about 0.3 to about 0.4. In other embodiments, ABIis in the range of from about 0.4 to about 1.0, from about 0.5 to about1.0, or from about 0.6 to about 1.0, from about 0.7 to about 1.0, fromabout 0.8 to about 1.0, or from about 0.9 to about 1.0.

Another characteristic of the inventive ethylene/α-olefin interpolymeris that the inventive ethylene/α-olefin interpolymer comprises at leastone polymer fraction which can be obtained by preparative TREF, whereinthe fraction has a block index greater than about 0.1 and up to about1.0 and a molecular weight distribution, M_(w)/M_(n), greater than abouts 1.3. In some embodiments, the polymer fraction has a block indexgreater than about 0.6 and up to about 1.0, greater than about 0.7 andup to about 1.0, greater than about 0.8 and up to about 1.0, or greaterthan about 0.9 and up to about 1.0. In other embodiments, the polymerfraction has a block index greater than about 0.1 and up to about 1.0,greater than about 0.2 and up to about 1.0, greater than about 0.3 andup to about 1.0, greater than about 0.4 and up to about 1.0, or greaterthan about 0.4 and up to about 1.0. In still other embodiments, thepolymer fraction has a block index greater than about 0.1 and up toabout 0.5, greater than about 0.2 and up to about 0.5, greater thanabout 0.3 and up to about 0.5, or greater than about 0.4 and up to about0.5. In yet other embodiments, the polymer fraction has a block indexgreater than about 0.2 and up to about 0.9, greater than about 0.3 andup to about 0.8, greater than about 0.4 and up to about 0.7, or greaterthan about 0.5 and up to about 0.6.

For copolymers of ethylene and an α-olefin, the inventive polymerspreferably possess (1) a PDI of at least 1.3, more preferably at least1.5, at least 1.7, or at least 2.0, and most preferably at least 2.6, upto a maximum value of 5.0, more preferably up to a maximum of 3.5, andespecially up to a maximum of 2.7; (2) a heat of fusion of 80 J/g orless; (3) an ethylene content of at least 50 weight percent; (4) a glasstransition temperature, T_(g), of less than −25° C., more preferablyless than −30° C., and/or (5) one and only one T_(m).

Further, the inventive polymers can have, alone or in combination withany other properties disclosed herein, a storage modulus, G′, such thatlog (G′) is greater than or equal to 400 kPa, preferably greater than orequal to 1.0 MPa, at a temperature of 100° C. Moreover, the inventivepolymers possess a relatively flat storage modulus as a function oftemperature in the range from 0 to 100° C. (illustrated in FIG. 6) thatis characteristic of block copolymers, and heretofore unknown for anolefin copolymer, especially a copolymer of ethylene and one or moreC₃₋₈ aliphatic α-olefins. (By the term “relatively flat” in this contextis meant that log G′ (in Pascals) decreases by less than one order ofmagnitude between 50 and 100° C., preferably between 0 and 100° C.).

The inventive interpolymers may be further characterized by athermomechanical analysis penetration depth of 1 mm at a temperature ofat least 90° C. as well as a flexural modulus of from 3 kpsi (20 MPa) to13 kpsi (90 MPa). Alternatively, the inventive interpolymers can have athermomechanical analysis penetration depth of 1 mm at a temperature ofat least 104° C. as well as a flexural modulus of at least 3 kpsi (20MPa). They may be characterized as having an abrasion resistance (orvolume loss) of less than 90 mm³. FIG. 7 shows the TMA (1 mm) versusflex modulus for the inventive polymers, as compared to other knownpolymers. The inventive polymers have significantly betterflexibility-heat resistance balance than the other polymers.

Additionally, the ethylene/α-olefin interpolymers can have a melt index,I₂, from 0.01 to 2000 g/10 minutes, preferably from 0.01 to 1000 g/10minutes, more preferably from 0.01 to 500 g/10 minutes, and especiallyfrom 0.01 to 100 g/10 minutes. In certain embodiments, theethylene/α-olefin interpolymers have a melt index, I₂, from 0.01 to 10g/10 minutes, from 0.5 to 50 g/10 minutes, from 1 to 30 g/10 minutes,from 1 to 6 g/10 minutes or from 0.3 to 10 g/10 minutes. In certainembodiments, the melt index for the ethylene/α-olefin polymers is 1 g/10minutes, 3 g/10 minutes or 5 g/10 minutes.

The polymers can have molecular weights, M_(w), from 1,000 g/mole to5,000,000 g/mole, preferably from 1000 g/mole to 1,000,000, morepreferably from 10,000 g/mole to 500,000 g/mole, and especially from10,000 g/mole to 300,000 g/mole. The density of the inventive polymerscan be from 0.80 to 0.99 g/cm³ and preferably for ethylene containingpolymers from 0.85 g/cm³ to 0.97 g/cm³. In certain embodiments, thedensity of the ethylene/α-olefin polymers ranges from 0.860 to 0.925g/cm³ or 0.867 to 0.910 g/cm³.

The process of making the polymers has been disclosed in the followingpatent applications: U.S. Provisional Application No. 60/553,906, filedMar. 17, 2004; U.S. Provisional Application No. 60/662,937, filed Mar.17, 2005; U.S. Provisional Application No. 60/662,939, filed Mar. 17,2005; U.S. Provisional Application No. 60/5662938, filed Mar. 17, 2005;PCT Application No. PCT/US2005/008916, filed Mar. 17, 2005; PCTApplication No. PCT/US2005/008915, filed Mar. 17, 2005; and PCTApplication No. PCT/US2005/008917, filed Mar. 17, 2005, all of which areincorporated by reference herein in their entirety. For example, onesuch method comprises contacting ethylene and optionally one or moreaddition polymerizable monomers other than ethylene under additionpolymerization conditions with a catalyst composition comprising:

the admixture or reaction product resulting from combining:

(A) a first olefin polymerization catalyst having a high comonomerincorporation index,

(B) a second olefin polymerization catalyst having a comonomerincorporation index less than 90 percent, preferably less than 50percent, most preferably less than 5 percent of the comonomerincorporation index of catalyst (A), and

(C) a chain shuttling agent.

Representative catalysts and chain shuttling agent are as follows.

Catalyst (A1) is[N-(2,6-di(1-methylethyl)phenyl)amido)(2-isopropylphenyl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafniumdimethyl, prepared according to the teachings of WO 03/40195,2003US0204017, U.S. Ser. No. 10/429,024, filed May 2, 2003, and WO04/24740.

Catalyst (A2) is[N-(2,6-di(1-methylethyl)phenyl)amido)(2-methylphenyl)(1,2-phenylene-(6-pyridin-2-diyl)methane)]hafniumdimethyl, prepared according to the teachings of WO 03/40195,2003US0204017, U.S. Ser. No. 10/429,024, filed May 2, 2003, and WO04/24740.

Catalyst (A3) isbis[N,N′″-(2,4,6-tri(methylphenyl)amido)ethylenediamine]hafniumdibenzyl.

Catalyst (A4) isbis((2-oxoyl-3-(dibenzo-1H-pyrrole-1-yl)-5-(methyl)phenyl)-2-phenoxymethyl)cyclohexane-1,2-diylzirconium (IV) dibenzyl, prepared substantially according to theteachings of US-A-2004/0010103.

Catalyst (B1) is1,2-bis-(3,5-di-t-butylphenylene)(1-(N-(1-methylethyl)immino)methyl)(2-oxoyl)zirconium dibenzyl

Catalyst (B2) is1,2-bis-(3,5-di-t-butylphenylene)(1-(N-(2-methylcyclohexyl)-immino)methyl)(2-oxoyl)zirconium dibenzyl

Catalyst (C1) is(t-butylamido)dimethyl(3-N-pyrrolyl-1,2,3,3a,7a-η-inden-1-yl)silanetitaniumdimethyl prepared substantially according to the techniques of U.S. Pat.No. 6,268,444:

Catalyst (C2) is(t-butylamido)di(4-methylphenyl)(2-methyl-1,2,3,3a,7a-η-inden-1-yl)silanetitaniumdimethyl prepared substantially according to the teachings ofUS-A-2003/004286:

Catalyst (C3) is(t-butylamido)di(4-methylphenyl)(2-methyl-1,2,3,3a,8a-η-s-indacen-1-yl)silanetitaniumdimethyl prepared substantially according to the teachings ofUS-A-2003/004286:

Catalyst (D1) is bis(dimethyldisiloxane)(indene-1-yl)zirconiumdichloride available from Sigma-Aldrich:

Shuttling Agents The shuttling agents employed include diethylzinc,di(i-butyl)zinc, di(n-hexyl)zinc, triethylaluminum, trioctylaluminum,triethylgallium, i-butylaluminum bis(dimethyl(t-butyl)siloxane),i-butylaluminum bis(di(trimethylsilyl)amide), n-octylaluminumdi(pyridine-2-methoxide), bis(n-octadecyl)i-butylaluminum,i-butylaluminum bis(di(n-pentyl)amide), n-octylaluminumbis(2,6-di-t-butylphenoxide, n-octylaluminum di(ethyl(1-naphthyl)amide),ethylaluminum bis(t-butyldimethylsiloxide), ethylaluminumdi(bis(trimethylsilyl)amide), ethylaluminumbis(2,3,6,7-dibenzo-1-azacycloheptaneamide), n-octylaluminumbis(2,3,6,7-dibenzo-1-azacycloheptaneamide), n-octylaluminumbis(dimethyl(t-butyl)siloxide, ethylzinc (2,6-diphenylphenoxide), andethylzinc (t-butoxide).

Preferably, the foregoing process takes the form of a continuoussolution process for forming block copolymers, especially multi-blockcopolymers, preferably linear multi-block copolymers of two or moremonomers, more especially ethylene and a C₃₋₂₀ olefin or cycloolefin,and most especially ethylene and a C₄₋₂₀ α-olefin, using multiplecatalysts that are incapable of interconversion. That is, the catalystsare chemically distinct. Under continuous solution polymerizationconditions, the process is ideally suited for polymerization of mixturesof monomers at high monomer conversions. Under these polymerizationconditions, shuttling from the chain shuttling agent to the catalystbecomes advantaged compared to chain growth, and multi-block copolymers,especially linear multi-block copolymers are formed in high efficiency.

The inventive interpolymers may be differentiated from conventional,random copolymers, physical blends of polymers, and block copolymersprepared via sequential monomer addition, fluxional catalysts, anionicor cationic living polymerization techniques. In particular, compared toa random copolymer of the same monomers and monomer content atequivalent crystallinity or modulus, the inventive interpolymers havebetter (higher) heat resistance as measured by melting point, higher TMApenetration temperature, higher high-temperature tensile strength,and/or higher high-temperature torsion storage modulus as determined bydynamic mechanical analysis. Compared to a random copolymer containingthe same monomers and monomer content, the inventive interpolymers havelower compression set, particularly at elevated temperatures, lowerstress relaxation, higher creep resistance, higher tear strength, higherblocking resistance, faster setup due to higher crystallization(solidification) temperature, higher recovery (particularly at elevatedtemperatures), better abrasion resistance, higher retractive force, andbetter oil and filler acceptance.

The inventive interpolymers also exhibit a unique crystallization andbranching distribution relationship. That is, the inventiveinterpolymers have a relatively large difference between the tallestpeak temperature measured using CRYSTAF and DSC as a function of heat offusion, especially as compared to random copolymers containing the samemonomers and monomer level or physical blends of polymers, such as ablend of a high density polymer and a lower density copolymer, atequivalent overall density. It is believed that this unique feature ofthe inventive interpolymers is due to the unique distribution of thecomonomer in blocks within the polymer backbone. In particular, theinventive interpolymers may comprise alternating blocks of differingcomonomer content (including homopolymer blocks). The inventiveinterpolymers may also comprise a distribution in number and/or blocksize of polymer blocks of differing density or comonomer content, whichis a Schultz-Flory type of distribution. In addition, the inventiveinterpolymers also have a unique peak melting point and crystallizationtemperature profile that is substantially independent of polymerdensity, modulus, and morphology. In a preferred embodiment, themicrocrystalline order of the polymers demonstrates characteristicspherulites and lamellae that are distinguishable from random or blockcopolymers, even at PDI values that are less than 1.7, or even less than1.5, down to less than 1.3.

Moreover, the inventive interpolymers may be prepared using techniquesto influence the degree or level of blockiness. That is the amount ofcomonomer and length of each polymer block or segment can be altered bycontrolling the ratio and type of catalysts and shuttling agent as wellas the temperature of the polymerization, and other polymerizationvariables. A surprising benefit of this phenomenon is the discovery thatas the degree of blockiness is increased, the optical properties, tearstrength, and high temperature recovery properties of the resultingpolymer are improved. In particular, haze decreases while clarity, tearstrength, and high temperature recovery properties increase as theaverage number of blocks in the polymer increases. By selectingshuttling agents and catalyst combinations having the desired chaintransferring ability (high rates of shuttling with low levels of chaintermination) other forms of polymer termination are effectivelysuppressed. Accordingly, little if any β-hydride elimination is observedin the polymerization of ethylene/α-olefin comonomer mixtures accordingto embodiments of the invention, and the resulting crystalline blocksare highly, or substantially completely, linear, possessing little or nolong chain branching.

Polymers with highly crystalline chain ends can be selectively preparedin accordance with embodiments of the invention. In elastomerapplications, reducing the relative quantity of polymer that terminateswith an amorphous block reduces the intermolecular dilutive effect oncrystalline regions. This result can be obtained by choosing chainshuttling agents and catalysts having an appropriate response tohydrogen or other chain terminating agents. Specifically, if thecatalyst which produces highly crystalline polymer is more susceptibleto chain termination (such as by use of hydrogen) than the catalystresponsible for producing the less crystalline polymer segment (such asthrough higher comonomer incorporation, regio-error, or atactic polymerformation), then the highly crystalline polymer segments willpreferentially populate the terminal portions of the polymer. Not onlyare the resulting terminated groups crystalline, but upon termination,the highly crystalline polymer forming catalyst site is once againavailable for reinitiation of polymer formation. The initially formedpolymer is therefore another highly crystalline polymer segment.Accordingly, both ends of the resulting multi-block copolymer arepreferentially highly crystalline.

The ethylene α-olefin interpolymers used in the embodiments of theinvention are preferably interpolymers of ethylene with at least oneC₃-C₂₀ α-olefin. Copolymers of ethylene and a C₃-C₂₀ α-olefin areespecially preferred. The interpolymers may further comprise C₄-C₁₈diolefin and/or alkenylbenzene. Suitable unsaturated comonomers usefulfor polymerizing with ethylene include, for example, ethylenicallyunsaturated monomers, conjugated or nonconjugated dienes, polyenes,alkenylbenzenes, etc. Examples of such comonomers include C₃-C₂₀α-olefins such as propylene, isobutylene, 1-butene, 1-hexene, 1-pentene,4-methyl-1-pentene, 1-heptene, 1-octene, 1-nonene, 1-decene, and thelike. 1-Butene and 1-octene are especially preferred. Other suitablemonomers include styrene, halo- or alkyl-substituted styrenes,vinylbenzocyclobutane, 1,4-hexadiene, 1,7-octadiene, and naphthenics(e.g., cyclopentene, cyclohexene and cyclooctene).

While ethylene/α-olefin interpolymers are preferred polymers, otherethylene/olefin polymers may also be used. Olefins as used herein referto a family of unsaturated hydrocarbon-based compounds with at least onecarbon-carbon double bond. Depending on the selection of catalysts, anyolefin may be used in embodiments of the invention. Preferably, suitableolefins are C₃-C₂₀ aliphatic and aromatic compounds containing vinylicunsaturation, as well as cyclic compounds, such as cyclobutene,cyclopentene, dicyclopentadiene, and norbornene, including but notlimited to, norbornene substituted in the 5 and 6 position with C₁-C₂₀hydrocarbyl or cyclohydrocarbyl groups. Also included are mixtures ofsuch olefins as well as mixtures of such olefins with C₄-C₄₀ diolefincompounds.

Examples of olefin monomers include, but are not limited to propylene,isobutylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene,1-nonene, 1-decene, and 1-dodecene, 1-tetradecene, 1-hexadecene,1-octadecene, 1-eicosene, 3-methyl-1-butene, 3-methyl-1-pentene,4-methyl-1-pentene, 4,6-dimethyl-1-heptene, 4-vinylcyclohexene,vinylcyclohexane, norbornadiene, ethylidene norbornene, cyclopentene,cyclohexene, dicyclopentadiene, cyclooctene, C₄-C₄₀ dienes, includingbut not limited to 1,3-butadiene, 1,3-pentadiene, 1,4-hexadiene,1,5-hexadiene, 1,7-octadiene, 1,9-decadiene, other C₄-C₄₀ α-olefins, andthe like. In certain embodiments, the α-olefin is propylene, 1-butene,1-pentene, 1-hexene, 1-octene or a combination thereof. Although anyhydrocarbon containing a vinyl group potentially may be used inembodiments of the invention, practical issues such as monomeravailability, cost, and the ability to conveniently remove unreactedmonomer from the resulting polymer may become more problematic as themolecular weight of the monomer becomes too high.

The polymerization processes described herein are well suited for theproduction of olefin polymers comprising monovinylidene aromaticmonomers including styrene, o-methyl styrene, p-methyl styrene,t-butylstyrene, and the like. In particular, interpolymers comprisingethylene and styrene can be prepared by following the teachings herein.Optionally, copolymers comprising ethylene, styrene and a C₃-C₂₀ alphaolefin, optionally comprising a C₄-C₂₀ diene, having improved propertiescan be prepared.

Suitable non-conjugated diene monomers can be a straight chain, branchedchain or cyclic hydrocarbon diene having from 6 to 15 carbon atoms.Examples of suitable non-conjugated dienes include, but are not limitedto, straight chain acyclic dienes, such as 1,4-hexadiene, 1,6-octadiene,1,7-octadiene, 1,9-decadiene, branched chain acyclic dienes, such as5-methyl-1,4-hexadiene; 3,7-dimethyl-1,6-octadiene;3,7-dimethyl-1,7-octadiene and mixed isomers of dihydromyricene anddihydroocinene, single ring alicyclic dienes, such as1,3-cyclopentadiene; 1,4-cyclohexadiene; 1,5-cyclooctadiene and1,5-cyclododecadiene, and multi-ring alicyclic fused and bridged ringdienes, such as tetrahydroindene, methyl tetrahydroindene,dicyclopentadiene, bicyclo-(2,2,1)-hepta-2,5-diene; alkenyl, alkylidene,cycloalkenyl and cycloalkylidene norbornenes, such as5-methylene-2-norbornene (MNB); 5-propenyl-2-norbornene,5-isopropylidene-2-norbornene, 5-(4-cyclopentenyl)-2-norbornene,5-cyclohexylidene-2-norbornene, 5-vinyl-2-norbornene, and norbornadiene.Of the dienes typically used to prepare EPDMs, the particularlypreferred dienes are 1,4-hexadiene (HD), 5-ethylidene-2-norbornene(ENB), 5-vinylidene-2-norbornene (VNB), 5-methylene-2-norbornene (MNB),and dicyclopentadiene (DCPD). The especially preferred dienes are5-ethylidene-2-norbornene (ENB) and 1,4-hexadiene (HD).

One class of desirable polymers that can be made in accordance withembodiments of the invention are elastomeric interpolymers of ethylene,a C₃-C₂₀ α-olefin, especially propylene, and optionally one or morediene monomers. Preferred α-olefins for use in this embodiment of thepresent invention are designated by the formula CH₂═CHR*, where R* is alinear or branched alkyl group of from 1 to 12 carbon atoms. Examples ofsuitable α-olefins include, but are not limited to, propylene,isobutylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, and1-octene. A particularly preferred α-olefin is propylene. The propylenebased polymers are generally referred to in the art as EP or EPDMpolymers. Suitable dienes for use in preparing such polymers, especiallymulti-block EPDM type polymers include conjugated or non-conjugated,straight or branched chain-, cyclic- or polycyclic-dienes comprisingfrom 4 to 20 carbons. Preferred dienes include 1,4-pentadiene,1,4-hexadiene, 5-ethylidene-2-norbornene, dicyclopentadiene,cyclohexadiene, and 5-butylidene-2-norbornene. A particularly preferreddiene is 5-ethylidene-2-norbornene.

Because the diene containing polymers comprise alternating segments orblocks containing greater or lesser quantities of the diene (includingnone) and α-olefin (including none), the total quantity of diene andα-olefin may be reduced without loss of subsequent polymer properties.That is, because the diene and α-olefin monomers are preferentiallyincorporated into one type of block of the polymer rather than uniformlyor randomly throughout the polymer, they are more efficiently utilizedand subsequently the crosslink density of the polymer can be bettercontrolled. Such crosslinkable elastomers and the cured products haveadvantaged properties, including higher tensile strength and betterelastic recovery.

In some embodiments, the inventive interpolymers made with two catalystsincorporating differing quantities of comonomer have a weight ratio ofblocks formed thereby from 95:5 to 5:95. The elastomeric polymersdesirably have an ethylene content of from 20 to 90 percent, a dienecontent of from 0.1 to 10 percent, and an α-olefin content of from 10 to80 percent, based on the total weight of the polymer. Furtherpreferably, the multi-block elastomeric polymers have an ethylenecontent of from 60 to 90 percent, a diene content of from 0.1 to 10percent, and an α-olefin content of from 10 to 40 percent, based on thetotal weight of the polymer. Preferred polymers are high molecularweight polymers, having a weight average molecular weight (Mw) from10,000 to about 2,500,000, preferably from 20,000 to 500,000, morepreferably from 20,000 to 350,000, and a polydispersity less than 3.5,more preferably less than 3.0, and a Mooney viscosity (ML (1+4) 125° C.)from 1 to 250. More preferably, such polymers have an ethylene contentfrom 65 to 75 percent, a diene content from 0 to 6 percent, and anα-olefin content from 20 to 35 percent.

The ethylene/α-olefin interpolymers can be functionalized byincorporating at least one functional group in its polymer structure.Exemplary functional groups may include, for example, ethylenicallyunsaturated mono- and di-functional carboxylic acids, ethylenicallyunsaturated mono- and di-functional carboxylic acid anhydrides, saltsthereof and esters thereof. Such functional groups may be grafted to anethylene/α-olefin interpolymer, or it may be copolymerized with ethyleneand an optional additional comonomer to form an interpolymer ofethylene, the functional comonomer and optionally other comonomer(s).Means for grafting functional groups onto polyethylene are described forexample in U.S. Pat. Nos. 4,762,890, 4,927,888, and 4,950,541, thedisclosures of these patents are incorporated herein by reference intheir entirety. One particularly useful functional group is malicanhydride.

The amount of the functional group present in the functionalinterpolymer can vary. The functional group can typically be present ina copolymer-type functionalized interpolymer in an amount of at leastabout 1.0 weight percent, preferably at least about 5 weight percent,and more preferably at least about 7 weight percent. The functionalgroup will typically be present in a copolymer-type functionalizedinterpolymer in an amount less than about 40 weight percent, preferablyless than about 30 weight percent, and more preferably less than about25 weight percent.

Preparation of Soft Foams

The soft foams disclosed herein can be prepared from a foamablecomposition comprising at least one blowing agent and at least oneethylene/α-olefin interpolymer disclosed herein. Optionally, thefoamable composition may further comprise at least a second polymercomponent, at least one other additive or a combination thereof.Non-limiting examples of suitable additives include cross-linkingagents, grafting initiators, cross-linking catalysts, blowing agentactivators (e.g., zinc oxide, zinc stearate and the like), coagents(e.g., triallyl cyanurate), plasticizers, colorants or pigments,stability control agents, nucleating agents, fillers, antioxidants, acidscavengers, ultraviolet stabilizers, flame retardants, lubricants,processing aids, extrusion aids, and combinations thereof. In someembodiments, the foamable composition further comprises a cross-linkingagent. In other embodiments, the foamable composition does not comprisea cross-linking agent

The soft foams disclosed herein may take any physical forms known in theart, such as sphere, cylinder, disk, cube, prism, sheet, plank, foamslab stock or irregular shapes. Further, they can be injection moldedarticles, compression molded articles, or extruded articles. Otheruseful forms are expandable or foamable particles, moldable foamparticles, or beads, and articles formed by expansion and/or coalescingand welding of those particles.

In some soft foam applications such as acoustical insulation, vibrationcontrol, cushioning, specialty packaging, automotive soft touch, andimpact absorption, the soft foams can be substantially noncross-linkedor uncross-linked. A soft foam is substantially noncross-linked oruncross-linked when the foam contains no more than 5% gel per ASTMD-2765-84 Method A. However, a slight degree of cross-linking, which canoccur naturally without the use of cross-linking agents or radiation, ispermissible. In some embodiments, the soft foam disclosed hereincontains no more than 10% of gel, no more than 5% of gel, no more than 4of % gel, no more than 3% of gel, no more than 2% of gel, no more than1% gel, no more than 0.5% of gel, no more than 0.1% of gel, or no morethan 0.01% of gel per ASTM D-2765-84 Method A. In other embodiments, thesoft foam disclosed herein contains no more than 5% of gel. In furtherembodiments, the soft foam disclosed herein contains no more than 3% ofgel. In further embodiments, the soft foam disclosed herein contains nomore than 1% of gel. In further embodiments, the soft foam disclosedherein contains no more than 0.5% of gel.

The soft foams disclosed herein can have a density between about 10 and150 kg/m³, from about 10 to about 100 kg/m³, or from about 10 to about50 kg/m³. Further, the soft foams can have an average cell size fromabout 0.05 to about 5.0 mm, from about 0.2 to about 2.0 mm, from about0.1 to about 1.5 mm, from about 0.1 to about 1.0 mm, or from about 0.2to about 0.6 mm according to ASTM D3576.

The soft foams disclosed herein can be either closed-celled oropen-celled. A foam is a closed cell foam when the foam contains 80% ormore closed cells or less than 20% open cells according to ASTM D2856-A.In some embodiments, the soft foams disclosed herein can have less thanabout 1% open cells, less than about 10% open cells, less than about 20%open cells, less than about 30% open cells, less than about 40% opencells, less than about 50% open cells, less than about 60% open cells,less than about 70% open cells, less than about 80% open cells or lessthan about 90% open cells. In other embodiments, the soft foamsdisclosed herein can have between about 10% and about 90% open cells,between about 10% and about 50% open cells, between about 50% and about90% open cells, or between about 10% and about 30% open cells.

In some embodiments, the foamable composition comprises theethylene/α-olefin interpolymer disclosed herein. In other embodiments,the foamable composition comprises a polymer blend (hereinafter “polymerblend”) comprising the ethylene/α-olefin interpolymer and a secondpolymer component. Some non-limiting examples of the second polymercomponent include EVA, polyolefins (e.g., polyethylene andpolypropylene), foamable polymers (e.g., polystyrene, ABS, SBS and thelike) and combinations thereof. In some embodiments, the second polymercomponent is EVA, polyethylene, polypropylene, polystyrene, ABS, SBS ora combination thereof. In other embodiments, the second polymercomponent is blended with the ethylene/α-olefin interpolymer beforeadded to the foamable composition. In other embodiments, the secondpolymer component is added directly to the foamable composition withoutpre-blending with the ethylene/α-olefin interpolymer.

The weight ratio of the ethylene/α-olefin interpolymer to the secondpolymer component in the polymer blend can be between about 1:99 andabout 99:1, between about 1:50 and about 50:1, between about 1:25 andabout 25:1, between about 1:10 and about 10:1, between about 1:9 andabout 9:1, between about 1:8 and about 8:1, between about 1:7 and about7:1, between about 1:6 and about 6:1, between about 1:5 and about 5:1,between about 1:4 and about 4:1, between about 1:3 and about 3:1,between about 1:2 and about 2:1, between about 3:7 and about 7:3 orbetween about 2:3 and about 3:2.

In some embodiments, the second polymer component is a polyolefin. Anypolyolefin that is partially or totally compatible with theethylene/α-olefin interpolymer may be used. Non-limiting examples ofsuitable polyolefins include polyethylenes; polypropylenes;polybutylenes (e.g., polybutene-1); polypentene-1; polyhexene-1;polyoctene-1; polydecene-1; poly-3-methylbutene-1;poly-4-methylpentene-1; polyisoprene; polybutadiene; poly-1,5-hexadiene;interpolymers derived from olefins; interpolymers derived from olefinsand other polymers such as polyvinyl chloride, polystyrene,polyurethane, and the like; and mixtures thereof. In some embodiments,the polyolefin is a homopolymer such as polyethylene, polypropylene,polybutylene, polypentene-1, poly-3-methylbutene-1,poly-4-methylpentene-1, polyisoprene, polybutadiene, poly-1,5-hexadiene,polyhexene-1, polyoctene-1 and polydecene-1.

Some non-limiting examples of suitable polyethylenes include ultra lowdensity polyethylene (ULDPE), linear low density polyethylene (LLDPE),low density polyethylene (LDPE), medium density polyethylene (MDPE),high density polyethylene (HDPE), high molecular weight high densitypolyethylene (HMW-HDPE), ultra high molecular weight polyethylene(UHMW-PE) and combinations thereof. Some non-limiting examples ofpolypropylenes include low density polypropylene (LDPP), high densitypolypropylene (HDPP), high-melt strength polypropylene (HMS-PP) andcombination thereof. In some embodiments, the second polymer componentis or comprises high-melt-strength polypropylene (HMS-PP), low densitypolyethylene (LDPE) or a combination thereof.

The blowing agents suitable for making the soft foams disclosed hereincan include, but are not limited to, inorganic blowing agents, organicblowing agents, chemical blowing agents and combinations thereof. Someblowing agents are disclosed in Sendijarevic et al., “Polymeric FoamsAnd Foam Technology,” Hanser Gardner Publications, Cincinnati, Ohio, 2ndedition, Chapter 18, pages 505-547 (2004), which is incorporated hereinby reference.

Non-limiting examples of suitable inorganic blowing agents includecarbon dioxide, nitrogen, argon, water, air, nitrogen, and helium.Non-limiting examples of suitable organic blowing agents includealiphatic hydrocarbons having 1-6 carbon atoms, aliphatic alcoholshaving 1-3 carbon atoms, and fully and partially halogenated aliphatichydrocarbons having 1-4 carbon atoms. Non-limiting examples of suitablealiphatic hydrocarbons include methane, ethane, propane, n-butane,isobutane, n-pentane, isopentane, neopentane, and the like. Non-limitingexamples of suitable aliphatic alcohols include methanol, ethanol,n-propanol, and isopropanol. Non-limiting examples of suitable fully andpartially halogenated aliphatic hydrocarbons include fluorocarbons,chlorocarbons, and chlorofluorocarbons. Non-limiting examples ofsuitable fluorocarbons include methyl fluoride, perfluoromethane, ethylfluoride, 1,1-difluoroethane (HFC-152a), 1,1,1-trifluoroethane(HFC-143a), 1,1,1,2-tetrafluoro-ethane (HFC-134a), pentafluoroethane,difluoromethane, perfluoroethane, 2,2-difluoropropane,1,1,1-trifluoropropane, perfluoropropane, dichloropropane,difluoropropane, perfluorobutane, perfluorocyclobutane. Non-limitingexamples of suitable partially halogenated chlorocarbons andchlorofluorocarbons include methyl chloride, methylene chloride, ethylchloride, 1,1,1-trichloroethane, 1,1-dichloro-1-fluoroethane(HCFC-141b), 1-chloro-1,1 difluoroethane (HCFC-142b),1,1-dichloro-2,2,2-trifluoroethane (HCFC-123) and1-chloro-1,2,2,2-tetrafluoroethane(HCFC-124). Non-limiting examples ofsuitable fully halogenated chlorofluorocarbons includetrichloromonofluoromethane (CFC-11), dichlorodifluoromiethane (CFC-12),trichlorotrifluoroethane (CFC-113), 1,1,1-trifluoroethane,pentafluoroethane, dichlorotetrafluoroethane (CFC-114),chloroheptafluoropropane, and dichlorohexafluoropropane. Non-limitingexamples of suitable chemical blowing agents include azodicarbonamide,azodiisobutyro-nitrile, benezenesulfonhydrazide, 4,4-oxybenzenesulfonyl-semicarbazide, p-toluene sulfonyl semi-carbazide, bariumazodicarboxylate, N,N′-dimethyl-N,N′-dinitrosoterephthalamide, andtrihydrazino triazine. In some embodiments, the blowing agent isazodicarbonamide isobutane, CO₂, or a mixture of thereof.

The amount of the blowing agent in the foamable composition disclosedherein may be from about 0.1 to about 20 wt %, from about 0.1 to about10 wt %, or from about 0.1 to about 5 wt %, based on the weight of theethylene/α-olefin interpolymer or the polymer blend. In otherembodiments, the amount of the blowing agent is from about 0.2 to about5.0 moles per kilogram of the interpolymer or polymer blend, from about0.5 to about 3.0 moles per kilogram of the interpolymer or polymerblend, or from about 1.0 to about 2.50 moles per kilogram of theinterpolymer or polymer blend.

The soft foams disclosed herein can be perforated to enhance oraccelerate permeation of the blowing agent from the foam cells and/orair into the foam cells. In some embodiments, the soft foams areperforated to form channels which extend entirely through the soft foamfrom one surface to another or partially through the soft foam. Thechannels can be spaced up to about 2.5 centimeters or up to about 1.3centimeters apart. The channels can be present over substantially anentire surface of the soft foam and preferably are uniformly dispersedover the surface. In other embodiments, the soft foams can employ astability control agent of the type described below in combination withperforation to allow accelerated permeation or release of the blowingagent while maintaining a dimensionally stable foam. The teachings offoam perforation are disclosed in U.S. Pat. Nos. 5,424,016 and5,585,058, both of which are incorporated herein by reference.

Optionally, the foamable compositions disclosed herein may comprise across-linking agent. Any cross-linking agent that can cross-link theethylene/α-olefin interpolymer or the polymer blend disclosed herein canbe used. When used, the cross-linking agent can be incorporated into theethylene/α-olefin interpolymer or the polymer blend in the same manneras the blowing agent. The amount of the cross-linking agent in thefoamable compositions or soft foams can be from about greater than 0 toabout 10 wt %, from about 0.1 to about 7.5 wt %, or from about 1 toabout 5 wt % based on the weight of the ethylene/α-olefin interpolymeror the polymer blend.

When a cross-linking agent is used, the cross-linking of the soft foamscan be induced by activating the cross-linking agent in the foamablecomposition. The cross-linking agent can be activated by exposing it toa temperature above its decomposition temperature. Alternatively, thecross-linking agent can be activated by exposing it to a radiation thatcauses the generation of free radicals from the cross-linking agent.Similarly, the foaming or expansion of the soft foams disclosed hereincan be induced by activating the blowing agent in the foamablecomposition. In some embodiments, the blowing agent is activated byexposing it to a temperature above its activation temperature.Generally, the activations of the cross-linking and foaming can occureither simultaneously or sequentially. In some embodiments, theactivations occur simultaneously. In other embodiments, the activationof the cross-linking occurs first and the activation of the foamingoccurs next. In further embodiments, the activation of the foamingoccurs first and the activation of the cross-linking occurs next.

The foamable composition can be prepared or processed at a temperatureof less than 150° C. to prevent the decomposition of the blowing agentand the cross-linking agent if it is used. When radiation cross-linkingis used, the foamable composition can be prepared or processed at atemperature of less than 160° C. to prevent the decomposition of theblowing agent. In some embodiments, the foamable composition can beextruded or processed through a die of desired shape to form a foamablestructure. Next, the foamable structure can be expanded and perhapscross-linked if a cross-linking agent is used at an elevated temperature(e.g., from about 150° C. to about 250° C.) to activate the blowingagent and perhaps the cross-linking agent to form a foam structure. Insome embodiments, the foamable structure can be irradiated to cross-linkthe polymer material, which can then be expanded at the elevatedtemperature as described above. In other embodiments, the foamablestructure is not cross-linked.

Some suitable cross-linking agents have been disclosed in Zweifel Hanset al., “Plastics Additives Handbook,” Hanser Gardner Publications,Cincinnati, Ohio, 5th edition, Chapter 14, pages 725-812 (2001);Encyclopedia of Chemical Technology, Vol. 17, 2nd edition, IntersciencePublishers (1968); and Daniel Seem, “Organic Peroxides,” Vol. 1,Wiley-Interscience, (1970), all of which are incorporated herein byreference. In some embodiments, there is no cross-linking agent in thefoamable compositions or soft foams disclosed herein.

Non-limiting examples of suitable cross-linking agents includeperoxides, phenols, azides, aldehyde-amine reaction products,substituted ureas, substituted guanidines; substituted xanthates;substituted dithiocarbamates; sulfur-containing compounds, such asthiazoles, sulfenamides, thiuramidisulfides, paraquinonedioxime,dibenzoparaquinonedioxime, sulfur; imidazoles; silanes and combinationsthereof.

Non-limiting examples of suitable organic peroxide cross-linking agentsinclude alkyl peroxides, aryl peroxides, peroxyesters, peroxycarbonates,diacylperoxides, peroxyketals, cyclic peroxides and combinationsthereof. In some embodiments, the organic peroxide is dicumyl peroxide,t-butylisopropylidene peroxybenzene, 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di(t-butyl peroxy)hexane, t-butyl-cumyl peroxide, di-t-butyl peroxide,2,5-dimethyl-2,5-di-(t-butyl peroxy) hexyne or a combination thereof. Inone embodiment, the organic peroxide is dicumyl peroxide. Additionalteachings regarding organic peroxide cross-linking agents are disclosedin C. P. Park, supra, pp. 198-204, which is incorporated herein byreference.

Non-limiting examples of suitable azide cross-linking agents includeazidoformates, such as tetramethylenebis(azidoformate); aromaticpolyazides, such as 4,4′-diphenylmethane diazide; and sulfonazides, suchas p,p′-oxybis(benzene sulfonyl azide). The disclosure of azidecross-linking agents can be found in U.S. Pat. Nos. 3,284,421 and3,297,674, both of which are incorporated herein by reference.

The poly(sulfonyl azide) is any compound having at least two sulfonylazide groups (i.e., —SO₂N₃) that are reactive towards theethylene/α-olefin interpolymer disclosed herein. In some embodiments,the poly(sulfonyl azide)s have a structure of X—R—X wherein each X is—SO₂N₃ and R represents an unsubstituted or inertly substitutedhydrocarbyl, hydrocarbyl ether or silicon-containing group. In someembodiments, the R group has sufficient carbon, oxygen or silicon,preferably carbon, atoms to separate the sulfonyl azide groupssufficiently to permit a facile reaction between the ethylene/α-olefininterpolymer and the sulfonyl azide groups. In other embodiments, the Rgroup has at least 1, at least 2, or at least 3 carbon, oxygen orsilicon, preferably carbon, atoms between the sulfonyl azide groups. Theterm “inertly substituted” refers to substitution with atoms or groupswhich do not undesirably interfere with the desired reaction(s) ordesired properties of the resulting cross-linked polymers. Such groupsinclude fluorine, aliphatic or aromatic ethers, siloxanes and the like.Non-limiting examples of suitable structures of R include aryl, alkyl,alkaryl, arylalkyl, silanyl, heterocyclyl, and other inert groups. Insome embodiments, the R group includes at least one aryl group betweenthe sulfonyl groups. In other embodiments, the R group includes at leasttwo aryl groups (such as when R is 4,4′ diphenylether or 4,4′-biphenyl).When R is one aryl group, it is preferred that the group have more thanone ring, as in the case of naphthylene bis(sulfonyl azides). In someembodiments, the poly(sulfonyl)azides include 1,5-pentanebis(sulfonylazide), 1,8-octane bis(sulfonyl azide), 1,10-decanebis(sulfonyl azide), 1,10-octadecane bis(sulfonyl azide),1-octyl-2,4,6-benzene tris(sulfonyl azide), 4,4′-diphenyl etherbis(sulfonyl azide), 1,6-bis(4′-sulfonazidophenyl)hexane,2,7-naphthalene bis(sulfonyl azide), and mixed sulfonyl azides ofchlorinated aliphatic hydrocarbons containing an average of from 1 to 8chlorine atoms and from about 2 to 5 sulfonyl azide groups per molecule,and combinations thereof. In other embodiments, the poly(sulfonylazide)s include oxy-bis(4-sulfonylazidobenzene), 2,7-naphthalenebis(sulfonyl azido), 4,4′-bis(sulfonyl azido)biphenyl, 4,4′-diphenylether bis(sulfonyl azide) and bis(4-sulfonyl azidophenyl)methane, andcombinations thereof.

Non-limiting examples of suitable aldehyde-amine reaction productsinclude formaldehyde-ammonia, formaldehyde-ethylchloride-ammonia,acetaldehyde-ammonia, formaldehyde-aniline, butyraldehyde-aniline,heptaldehyde-aniline, and combinations thereof.

Non-limiting examples of suitable substituted ureas includetrimethylthiourea, diethylthiourea, dibutylthiourea, tripentylthiourea,1,3-bis(2-benzothiazolylmercaptomethyl)urea, N,N-diphenylthiourea, andcombinations thereof.

Non-limiting examples of suitable substituted guanidines includediphenylguanidine, di-o-tolylguanidine, diphenylguanidine phthalate, thedi-o-tolylguanidine salt of dicatechol borate, and combinations thereof.

Non-limiting examples of suitable substituted xanthates include zincethylxanthate, sodium isopropylxanthate, butylxanthic disulfide,potassium isopropylxanthate, zinc butylxanthate, and combinationsthereof.

Non-limiting examples of suitable dithiocarbamates include copperdimethyl-, zinc dimethyl-, tellurium diethyl-, cadmium dicyclohexyl-,lead dimethyl-, lead dimethyl-, selenium dibutyl-, zinc pentamethylene-,zinc didecyl-, zinc isopropyloctyl-dithiocarbamate, and combinationsthereof.

Non-limiting examples of suitable thiazoles include2-mercaptobenzothiazole, zinc mercaptothiazolyl mercaptide,2-benzothiazolyl-N,N-diethylthiocarbamyl sulfide,2,2′-dithiobis(benzothiazole), and combinations thereof.

Non-limiting examples of suitable imidazoles include2-mercaptoimidazoline 2-mercapto-4,4,6-trimethyldihydropyrimidine, andcombinations thereof.

Non-limiting examples of suitable sulfenamides includeN-t-butyl-2-benzothiazole-, N-cyclohexylbenzothiazole-,N,N-diisopropylbenzothiazole-,N-(2,6-dimethylmorpholino)-2-benzothiazole-,N,N-diethylbenzothiazole-sulfenamide, and combinations thereof.

Non-limiting examples of suitable thiuramidisulfides includeN,N′-diethyl-, tetrabutyl-, N,N′-diisopropyldioctyl-, tetramethyl-,N,N′-dicyclohexyl-, N,N′-tetralaurylthiuramidisulfide, and combinationsthereof.

In some embodiments, the cross-linking agents are silanes. Any silanethat can effectively graft to and/or cross-link the ethylene/α-olefininterpolymer or the polymer blend disclosed herein can be used.Non-limiting examples of suitable silane cross-linking agents includeunsaturated silanes that comprise an ethylenically unsaturatedhydrocarbyl group, such as a vinyl, allyl, isopropenyl, butenyl,cyclohexenyl or gamma-(meth)acryloxy allyl group, and a hydrolyzablegroup such as a hydrocarbyloxy, hydrocarbonyloxy, and hydrocarbylaminogroup. Non-limiting examples of suitable hydrolyzable groups includemethoxy, ethoxy, formyloxy, acetoxy, proprionyloxy, alkyl and arylaminogroups. In other embodiments, the silanes are the unsaturated alkoxysilanes which can be grafted onto the interpolymer. Some of thesesilanes and their preparation methods are more fully described in U.S.Pat. No. 5,266,627, which is incorporated herein by reference. Infurther embodiments, the silane cross-linking agents arevinyltrimethoxysilane, vinyltriethoxysilane,vinyltris(2-methoxyethoxy)silane, vinyltriacetoxysilane,vinylmethyldimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, andcombinations thereof.

The amount of the silane cross-linking agent can vary widely, dependingupon the nature of the ethylene/α-olefin interpolymer or the polymerblend, the silane employed, the processing conditions, the amount ofgrafting initiator, the ultimate application, and other factors. Whenvinyltrimethoxysilane (VTMOS) is used, the amount of VTMOS is generallyat least about 0.1 weight percent, at least about 0.5 weight percent, orat least about 1 weight percent, based on the combined weight of thesilane cross-linking agent and the interpolymer or the polymer blend.

Optionally, the foamable composition disclosed herein may comprise agrafting initiator. Those skilled in the art will be readily able toselect the amount of the grafting initiator based on the characteristicsof the ethylene/α-olefin interpolymer or the polymer blend, such asmolecular weight, molecular weight distribution, comonomer content, aswell as the presence of cross-linking enhancing coagents, additives, andthe like.

Optionally, the foamable composition disclosed herein may comprise acatalyst. Any cross-linking catalyst that can promote the cross-linkingof the ethylene/α-olefin interpolymer or the polymer blend can be used.Non-limiting examples of suitable catalysts include organic bases,carboxylic acids, and organometallic compounds. In some embodiments, thecatalyst includes organic titanates and complexes or carboxylates oflead, cobalt, iron, nickel, zinc and tin. In other embodiments, thecatalyst is or comprises dibutyltin dilaurate, dioctyltin maleate,dibutyltin diacetate, dibutyltin dioctanoate, stannous acetate, stannousoctanoate, lead naphthenate, zinc caprylate, cobalt naphthenate or acombination thereof. In further embodiments, the catalyst is orcomprises a tin carboxylate such as dibutyltin dilaurate and dioctyltinmaleate.

Alternatively, the cross-linking of the soft foam or foamablecomposition can be effected by using radiation. Non-limiting examples ofsuitable radiation include electron beam or beta ray, gamma rays,X-rays, or neutron rays. Radiation is believed to activate thecross-linking by generating radicals in the polymer which maysubsequently combine and cross-link. Additional teachings concerningradiation cross-linking are disclosed in C. P. Park, supra, pages198-204, which is incorporated herein by reference. In some embodiments,the soft foam or foamable composition is not cross-linked by radiation.

Those skilled in the art will be readily able to select the amount ofcross-linking agent, based on the desired cross-linking level, thecharacteristics of the polymer such as molecular weight, molecularweight distribution, comonomer content, the presence of cross-linkingenhancing coagents, other additives and the like. Since it is expresslycontemplated that the ethylene/α-olefin interpolymer can be blended withother polymers such as EVA and polyolefins prior to cross-linking, thoseskilled in the art may use the disclosure herein as a reference point inoptimizing the amount of the cross-linking agent for a particularpolymer in question.

Optionally, the soft foams or foamable compositions disclosed herein cancomprise at least one other additive. Any foam additive that can improveand/or control the processibility, appearance, physical, chemical,and/or mechanical properties of the foam structures or articles can beused. Any foam additive known to a person of ordinary skill in the artcan be incorporated in the soft foams disclosed herein. Non-limitingexamples of suitable other additives include cross-linking agents,grafting initiators, cross-linking catalysts, blowing agent activators(e.g., zinc oxide, zinc stearate and the like), coagents (e.g., triallylcyanurate), plasticizers, colorants or pigments, stability controlagents, nucleating agents, fillers, antioxidants, acid scavengers,ultraviolet (UV) stabilizers, flame retardants, lubricants, processingaids, extrusion aids, and combinations thereof. The total amount of theother additives can range from about greater than 0 to about 80%, fromabout 0.001% to about 70%, from about 0.01% to about 60%, from about0.1% to about 50%, from about 1% to about 40%, or from about 10% toabout 50% of the total weight of the foam. Some suitable additives havebeen described in Zweifel Hans et al., “Plastics Additives Handbook,”Hanser Gardner Publications, Cincinnati, Ohio, 5th edition (2001), whichis incorporated herein by reference in its entirety.

The soft foams or foamable compositions disclosed herein may optionallycomprise a stability control agent or gas permeation modifier. Anystability control agent that can enhance the dimensional stability ofthe soft foams can be used. Non-limiting examples of suitable stabilitycontrol agents include amides and esters of C₁₀₋₂₄ fatty acids. Suchagents are described in U.S. Pat. Nos. 3,644,230 and 4,214,054, both ofwhich are incorporated herein by reference. In some embodiments, thestability control agents include stearyl stearamide, glycerolmonostearate, glycerol monobehenate, sorbitol monostearate andcombinations thereof. In general, the amount of the stability controlagents is from about 0.1 to about 10 parts, from about 0.1 to about 5parts, or from about 0.1 to about 3 parts by weight per hundred parts byweight of the polymer. In some embodiment, the stability control agentis glycerol monostearate.

The foams or foamable compositions disclosed herein may optionallycomprise a nucleating agent. Any nucleating agent that can control thesize of foam cells can be used. Non-limiting examples of suitablenucleating agents include inorganic substances such as calciumcarbonate, talc, clay, titanium oxide, silica, barium sulfate,diatomaceous earth, citric acid, sodium bicarbonate, sodium carbonate,and combinations thereof. In some embodiments, the nucleating agent is acombination of citric acid and sodium bicarbonate or a combination ofcitric acid and sodium carbonate. In other embodiments, the nucleatingagent is HYDROCEROL® CF 20 from Clariant Corporation, Charlotte, N.C.The amount of nucleating agent employed can range from 0.01 to 5 partsby weight per hundred parts by weight of the polymer.

In some embodiments, the soft foams or foamable compositions disclosedherein comprise an antioxidant. Any antioxidant that can prevent theoxidation of the polymer components and organic additives in the softfoams can be added to the soft foams disclosed herein. Non-limitingexamples of suitable antioxidants include aromatic or hindered aminessuch as alkyl diphenylamines, phenyl-α-naphthylamine, alkyl or aralkylsubstituted phenyl-α-naphthylamine, alkylated p-phenylene diamines,tetramethyl-diaminodiphenylamine and the like; phenols such as2,6-di-t-butyl-4-methylphenol;1,3,5-trimethyl-2,4,6-tris(3′,5′-di-t-butyl-4′-hydroxybenzyl)benzene;tetrakis[(methylene(3,5-di-t-butyl-4-hydroxyhydrocinnamate)]methane(e.g., IRGANOX™ 1010, from Ciba Geigy, N.Y.); acryloyl modified phenols;octadecyl-3,5-di-t-butyl-4-hydroxycinnamate (e.g., IRGANOX™ 1076,commercially available from Ciba Geigy); phosphites and phosphonites;hydroxylamines; benzofuranone derivatives; and combinations thereof.Where used, the amount of the antioxidant in the foam can be from aboutgreater than 0 to about 5 wt %, from about 0.0001 to about 2.5 wt %,from about 0.001 to about 1 wt %, or from about 0.001 to about 0.5 wt %of the total weight of the foam. Some antioxidants have been describedin Zweifel Hans et al., “Plastics Additives Handbook,” Hanser GardnerPublications, Cincinnati, Ohio, 5th edition, Chapter 1, pages 1-140(2001), which is incorporated herein by reference.

In other embodiments, the soft foams or foamable compositions disclosedherein comprise a UV stabilizer that may prevent or reduce thedegradation of the foams by UV radiations. Any UV stabilizer that mayprevent or reduce the degradation of the foams by UV radiations can beadded to the soft foams disclosed herein. Non-limiting examples ofsuitable UV stabilizers include benzophenones, benzotriazoles, arylesters, oxanilides, acrylic esters, formamidines, carbon black, hinderedamines, nickel quenchers, hindered amines, phenolic antioxidants,metallic salts, zinc compounds and combinations thereof. Where used, theamount of the UV stabilizer in the foam can be from about greater than 0to about 5 wt %, from about 0.01 to about 3 wt %, from about 0.1 toabout 2 wt %, or from about 0.1 to about 1 wt % of the total weight ofthe foam. Some UV stabilizers have been described in Zweifel Hans etal., “Plastics Additives Handbook,” Hanser Gardner Publications,Cincinnati, Ohio, 5th edition, Chapter 2, pages 141-426 (2001), which isincorporated herein by reference.

In further embodiments, the soft foams or foamable compositionsdisclosed herein comprise a colorant or pigment. Any colorant or pigmentthat can change the look of the soft foams to human eyes can be added tothe foams disclosed herein. Non-limiting examples of suitable colorantsor pigments include inorganic pigments such as metal oxides such as ironoxide, zinc oxide, and titanium dioxide, mixed metal oxides, carbonblack, organic pigments such as anthraquinones, anthanthrones, azo andmonoazo compounds, arylamides, benzimidazolones, BONA lakes,diketopyrrolo-pyrroles, dioxazines, disazo compounds, diarylidecompounds, flavanthrones, indanthrones, isoindolinones, isoindolines,metal complexes, monoazo salts, naphthols, b-naphthols, naphthol AS,naphthol lakes, perylenes, perinones, phthalocyanines, pyranthrones,quinacridones, and quinophthalones, and combinations thereof. Whereused, the amount of the colorant or pigment in the soft foam can be fromabout greater than 0 to about 10 wt %, from about 0.1 to about 5 wt %,or from about 0.25 to about 2 wt % of the total weight of the foam. Somecolorants have been described in Zweifel Hans et al., “PlasticsAdditives Handbook,” Hanser Gardner Publications, Cincinnati, Ohio, 5thedition, Chapter 15, pages 813-882 (2001), which is incorporated hereinby reference.

Optionally, the soft foams or foamable compositions disclosed herein cancomprise a filler. Any filler which can be used to adjust, inter alia,volume, weight, costs, and/or technical performance can be added to thesoft foams disclosed herein. Non-limiting examples of suitable fillersinclude talc, calcium carbonate, chalk, calcium sulfate, clay, kaolin,silica, glass, fumed silica, mica, wollastonite, feldspar, aluminumsilicate, calcium silicate, alumina, hydrated alumina such as aluminatrihydrate, glass microsphere, ceramic microsphere, thermoplasticmicrosphere, barite, wood flour, glass fibers, carbon fibers, marbledust, cement dust, magnesium oxide, magnesium hydroxide, antimony oxide,zinc oxide, barium sulfate, titanium dioxide, titanates and combinationsthereof. In some embodiments, the filler is barium sulfate, talc,calcium carbonate, silica, glass, glass fiber, alumina, titaniumdioxide, or a mixture thereof. In other embodiments, the filler is talc,calcium carbonate, barium sulfate, glass fiber or a mixture thereof.Where used, the amount of the filler in the soft foam can be from aboutgreater than 0 to about 80 wt %, from about 0.1 to about 60 wt %, fromabout 0.5 to about 40 wt %, from about 1 to about 30 wt %, or from about10 to about 40 wt % of the total weight of the foam. Some fillers havebeen disclosed in U.S. Pat. No. 6,103,803 and Zweifel Hans et al.,“Plastics Additives Handbook,” Hanser Gardner Publications, Cincinnati,Ohio, 5th edition, Chapter 17, pages 901-948 (2001), both of which areincorporated herein by reference.

Optionally, the soft foams or foamable compositions disclosed herein cancomprise a lubricant. In general, the lubricant. Any lubricant that canbe used, inter alia, to modify the rheology of the molten foamablecompositions, to improve the surface finish of molded foam articles,and/or to facilitate the dispersion of fillers or pigments can be addedto the soft foams disclosed herein. Non-limiting examples of suitablelubricants include fatty alcohols and their dicarboxylic acid esters,fatty acid esters of short-chain alcohols, fatty acids, fatty acidamides, metal soaps, oligomeric fatty acid esters, fatty acid esters oflong-chain alcohols, montan waxes, polyethylene waxes, polypropylenewaxes, natural and synthetic paraffin waxes, fluoropolymers andcombinations thereof. Where used, the amount of the lubricant in thefoam can be from about greater than 0 to about 5 wt %, from about 0.1 toabout 4 wt %, or from about 0.1 to about 3 wt % of the total weight ofthe foam. Some suitable lubricants have been disclosed in Zweifel Hanset al., “Plastics Additives Handbook,” Hanser Gardner Publications,Cincinnati, Ohio, 5th edition, Chapter 5, pages 511-552 (2001), both ofwhich are incorporated herein by reference.

Optionally, the soft foams or foamable compositions disclosed herein cancomprise an antistatic agent. Any antistatic agent that can increase theconductivity of the soft foams and to prevent static charge accumulationcan be added to the foams disclosed herein. Non-limiting examples ofsuitable antistatic agents include conductive fillers (e.g., carbonblack, metal particles and other conductive particles), fatty acidesters (e.g., glycerol monostearate), ethoxylated alkylamines,diethanolamides, ethoxylated alcohols, alkylsulfonates, alkylphosphates,quaternary ammonium salts, alkylbetaines and combinations thereof. Whereused, the amount of the antistatic agent in the soft foam can be fromabout greater than 0 to about 5 wt %, from about 0.01 to about 3 wt %,or from about 0.1 to about 2 wt % of the total weight of the foam. Somesuitable antistatic agents have been disclosed in Zweifel Hans et al.,“Plastics Additives Handbook,” Hanser Gardner Publications, Cincinnati,Ohio, 5th edition, Chapter 10, pages 627-646 (2001), both of which areincorporated herein by reference.

The processes of making polyolefin foams are described in C. P. Park,“Polyolefin Foam”, Chapter 9 of Handbook of Polymer Foams andTechnology, edited by D. Klempner and K. C. Frisch, Hanser Publishers,Munich (1991), which is incorporated herein by reference.

The ingredients of the foamable composition can be mixed or blended inany suitable mixing or blending devices known to skilled artisans. Theingredients in the foamable composition can then be mixed at atemperature below the decomposition temperature of the blowing agent andperhaps the cross-linking agent if it is present to ensure that allingredients are homogeneously mixed and remain intact. After thefoamable composition is relatively homogeneously mixed, the compositionis shaped and then exposed to conditions (e.g. heat, pressure, shear,etc.) over a sufficient period of time to activate the blowing agent andperhaps the cross-linking agent to make the soft foam.

In some embodiments, the ingredients of the foamable composition can bemixed and melt blended by any mixing or blending device known to aperson of ordinary skill in the art. Non-limiting examples of suitablemixing or blending devices include extruders, mixers, blenders, mills,dispersers, homogenizers and the like. In other embodiments, the blowingagent is dry-blended with the ethylene/α-olefin interpolymer or thepolymer blend before the foamable composition is heated to a moltenform. In further embodiments, the blowing agent is added when thefoamable composition is in a molten phase. In some embodiments, thefoamable composition disclosed herein is extruded through a die wherethe cross-linking may be activated if a cross-linking agent is present.Then the extruded foamable composition may be exposed to an elevatedtemperature to activate the blowing agent to form the soft foams.

The soft foams disclosed herein can be prepared by conventionalextrusion foaming processes. The soft foam can generally be prepared byheating the ethylene/α-olefin interpolymer or the polymer blend to forma plasticized or melt polymer material, incorporating therein a blowingagent to form a foamable composition, and extruding the foamablecomposition through a die to form foam products. Prior to mixing withthe blowing agent, the ethylene/α-olefin interpolymer can be heated to atemperature at or above its glass transition temperature or meltingpoint. The blowing agent can be incorporated or mixed into the moltenethylene/α-olefin interpolymer by any means known in the art such aswith an extruder, mixer, blender, and the like. The blowing agent can bemixed with the molten ethylene/α-olefin interpolymer at an elevatedpressure sufficient to prevent substantial expansion of the moltenethylene/α-olefin interpolymer and to generally disperse the blowingagent homogeneously therein. Optionally, a nucleating agent can beblended in the interpolymer melt or dry blended with theethylene/α-olefin interpolymer prior to plasticizing or melting. Thefoamable composition can be cooled to a lower temperature to optimizephysical characteristics of the foam structure. The foamable compositioncan be then extruded or conveyed through a die of desired shape to azone of reduced or lower pressure to form the foam structure. The zoneof lower pressure can be at a pressure lower than that in which thefoamable composition is maintained prior to extrusion through the die.The lower pressure can be super-atmospheric or sub-atmospheric (vacuum),but is preferably at an atmospheric level.

The soft foam can be conveniently extruded in various shapes having apreferred foam thickness in the direction of minimum foam thickness inthe range from about 1 mm to about 100 mm or more. When the soft foam isin the form of a sheet, the soft foam can have a thickness in the rangefrom about 1 or 2 mm to about 15 mm. When the soft foam is in the formof a plank, the soft foam can have a thickness in the range from about15 mm to about 100 mm. The desired thickness depends in part on theapplication.

In some embodiments, the soft foams disclosed herein are formed in acoalesced strand form by extrusion of the ethylene/α-olefin interpolymerthrough a multi-orifice die. The orifices can be arranged so thatcontact between adjacent streams of the molten extrudate occurs duringthe foaming process and the contacting surfaces adhere to one anotherwith sufficient adhesion to result in a unitary foam structure. Thestreams of the molten extrudate exiting the die can take the form ofstrands or profiles, which can desirably foam, coalesce, and adhere toone another to form a unitary structure. Desirably, the coalescedindividual strands or profiles should remain adhered in a unitarystructure to prevent strand delamination under stresses encountered inpreparing, shaping, and using the foams. Apparatuses and methods forproducing foam structures in coalesced strand form are disclosed in U.S.Pat. Nos. 3,573,152 and 4,824,720, both of which are incorporated hereinby reference.

In other embodiments, the soft foams disclosed herein are formed by anaccumulating extrusion process as seen in U.S. Pat. No. 4,323,528, whichis incorporated by reference herein. In the accumulating extrusionprocess, low density foams having large lateral cross-sectional areasare prepared by: 1) forming under pressure a foamable composition of theethylene/α-olefin interpolyymer and a blowing agent at a temperature atwhich the viscosity of the foamable composition is sufficient to retainthe blowing agent when the foamable composition is allowed to expand; 2)extruding the foamable composition into a holding zone maintained at atemperature and pressure which does not allow the foamable compositionto foam, the holding zone having an outlet die defining an orificeopening into a zone of lower pressure at which the foamable compositionfoams, and an openable gate closing the die orifice; 3) periodicallyopening the gate; 4) substantially concurrently applying mechanicalpressure by a movable ram on the foamable composition to eject it fromthe holding zone through the die orifice into the zone of lowerpressure, at a rate greater than that at which substantial foaming inthe die orifice occurs and less than that at which substantialirregularities in cross-sectional area or shape occurs; and 5)permitting the ejected foamable composition to expand unrestrained in atleast one dimension to produce the foam structure.

In some embodiments, the soft foams disclosed herein are formed intonon-crosslinked foam beads suitable for molding into articles. To makethe foam beads, discrete ethylene/α-olefin interpolymer particles suchas granulated ethylene/α-olefin interpolymer pellets are: (1) suspendedin a liquid medium in which they are substantially insoluble such aswater; (2) impregnated with a blowing agent by introducing the blowingagent into the liquid medium at an elevated pressure and temperature inan autoclave or other pressure vessel; and (3) rapidly discharged intothe atmosphere or a region of reduced pressure to expand to form thefoam beads. This process is well taught in U.S. Pat. Nos. 4,379,859 and4,464,484, which are incorporated herein by reference.

In a derivative of the above process, styrene monomer can be impregnatedinto the suspended ethylene/α-olefin interpolymer pellets prior toimpregnation with blowing agent to form a graft interpolymer with theethylene/α-olefin interpolymer. The resulted graft interpolymer beadscan be cooled and discharged from the vessel substantially unexpanded.The beads are then expanded and molded by the conventional expandedpolystyrene bead molding process. The process of making some graftinterpolymer beads is described in U.S. Pat. No. 4,168,353, which isincorporated herein by reference.

The foam beads can be molded into articles by any method known to aperson of ordinary skill in the art. In some embodiments, the foam beadsare charged to the mold, compressed by compressing the mold, and heatedwith a heat source such as steam to effect coalescing and welding of thefoam beads to form the articles. In other embodiments, the foam beadsare impregnated with air or other blowing agent at an elevated pressureand temperature prior to charging to the mold. In further embodiments,the foam beads are heated prior to charging to the mold. The beads canthen be molded to blocks or shaped articles by a suitable molding methodknown in the art. Some of the methods are taught in U.S. Pat. Nos.3,504,068 and 3,953,558 and in C. P. Park, supra, p. 191, pp. 197-198,and pp. 227-229, all of which are incorporated herein by reference.

In some embodiments, the soft foams disclosed herein can be prepared byeither compression molding or injection molding. In other embodiments,the soft foams are prepared by compression molding at a temperatureabove the decomposition temperatures of the peroxide and the blowingagent which is followed by a post expansion when the mold open. Infurther embodiments, the soft foams are prepared by injection moldingthe ethylene/α-olefin interpolymer melts at temperatures below thedecomposition temperatures of the peroxide and the blowing agent intomolds at temperature above the decomposition temperatures of theperoxide and the blowing agent which is followed by a post expansionafter opening the molds (from about 160 to about 190° C.).

In some embodiments, microcellular thermoplastic vulcanizate (“TPV”)foams could be made using supercritical fluids (e.g., CO or N₂). Suchtechniques are taught in U.S. Pat. Nos. 5,158,986; 5,160,674; 5,334,356;5,866,053; 6,169,122; 6,284,810; and 6,294,115, which are incorporatedby reference herein in their entirety. The methods disclosed therein canbe used in embodiments of the invention with or without modifications.TPV compositions based on the inventive polymers disclosed herein aretaught in U.S. Provisional Application No. 60/718,186, filed Sep. 16,2005, which is incorporated by reference herein in its entirety. SuchTPV compositions could be used in embodiments of the invention to makemicrocellular TPV foams.

Blending of the Ingredients of the Foams

The ingredients of the soft foams, ie., the ethylene/α-olefininterpolymer, the blowing agent, the optional second polymer component(e.g., EVA, polyethylene, and polypropylene) and additives (e.g., thecross-linking agent) can be mixed or blended using methods known to aperson of ordinary skill in the art. Non-limiting examples of suitableblending methods include melt blending, solvent blending, extruding, andthe like.

In some embodiments, the ingredients of the soft foams are melt blendedby a method as described by Guerin et al. in U.S. Pat. No. 4,152,189.First, all solvents, if there are any, are removed from the ingredientsby heating to an appropriate elevated temperature of about 100° C. toabout 200° C. or about 150° C. to about 175° C. at a pressure of about 5torr (667 Pa) to about 10 torr (1333 Pa). Next, the ingredients areweighed into a vessel in the desired proportions and the foam is formedby heating the contents of the vessel to a molten state while stirring.

In other embodiments, the ingredients of the soft foams are processedusing solvent blending. First, the ingredients of the desired foam aredissolved in a suitable solvent and the mixture is then mixed orblended. Next, the solvent is removed to provide the foam.

In further embodiments, physical blending devices that can providedispersive mixing, distributive mixing, or a combination of dispersiveand distributive mixing can be used in preparing homogenous blends. Bothbatch and continuous methods of physical blending can be used.Non-limiting examples of batch methods include those methods usingBRABENDER® mixing equipments (e.g., BRABENDER PREP CENTER®, availablefrom C. W. Brabender Instruments, Inc., South Hackensack, N.J.) orBANBURY® internal mixing and roll milling (available from FarrelCompany, Ansonia, Conn.) equipment. Non-limiting examples of continuousmethods include single screw extruding, twin screw extruding, diskextruding, reciprocating single screw extruding, and pin barrel singlescrew extruding. In some embodiments, the additives can be added into anextruder through a feed hopper or feed throat during the extrusion ofthe ethylene/α-olefin interpolymer, the optional second polymercomponent or the foam. The mixing or blending of polymers by extrusionhas been described in C. Rauwendaal, “Polymer Extrusion”, HanserPublishers, New York, N.Y., pages 322-334 (1986), which is incorporatedherein by reference.

When one or more additives are required in the soft foams, the desiredamounts of the additives can be added in one charge or multiple chargesto the ethylene/α-olefin interpolymer, the second polymer component orthe polymer blend. Furthermore, the addition can take place in anyorder. In some embodiments, the additives are first added and mixed orblended with the ethylene/α-olefin interpolymer and then theadditive-containing interpolymer is blended with the second polymercomponent. In other embodiments, the additives are first added and mixedor blended with the second polymer component and then theadditive-containing second polymer component is blended with theethylene/α-olefin interpolymer. In further embodiments, theethylene/α-olefin interpolymer is blended with the second polymercomponent first and then the additives are blended with the polymerblend.

The following examples are presented to exemplify embodiments of theinvention. All numerical values are approximate. When numerical rangesare given, it should be understood that embodiments outside the statedranges may still fall within the scope of the invention. Specificdetails described in each example should not be construed as necessaryfeatures of the invention.

EXAMPLES

Testing Methods

In the examples that follow, the following analytical techniques areemployed:

GPC Method for Samples 1-4 and A-C

An automated liquid-handling robot equipped with a heated needle set to160° C. is used to add enough 1,2,4-trichlorobenzene stabilized with 300ppm Ionol to each dried polymer sample to give a final concentration of30 mg/mL. A small glass stir rod is placed into each tube and thesamples are heated to 160° C. for 2 hours on a heated, orbital-shakerrotating at 250 rpm. The concentrated polymer solution is then dilutedto 1 mg/ml using the automated liquid-handling robot and the heatedneedle set to 160° C.

A Symyx Rapid GPC system is used to determine the molecular weight datafor each sample. A Gilson 350 pump set at 2.0 ml/min flow rate is usedto pump helium-purged 1,2-dichlorobenzene stabilized with 300 ppm Ionolas the mobile phase through three Plgel 10 micrometer (μm) Mixed B 300mm×7.5 mm columns placed in series and heated to 160° C. A Polymer LabsELS 1000 Detector is used with the Evaporator set to 250° C., theNebulizer set to 165° C., and the nitrogen flow rate set to 1.8 SLM at apressure of 60-80 psi (400-600 kPa) N₂. The polymer samples are heatedto 160° C. and each sample injected into a 250 μl loop using theliquid-handling robot and a heated needle. Serial analysis of thepolymer samples using two switched loops and overlapping injections areused. The sample data is collected and analyzed using Symyx Epoch™software. Peaks are manually integrated and the molecular weightinformation reported uncorrected against a polystyrene standardcalibration curve.

Standard CRYSTAF Method

Branching distributions are determined by crystallization analysisfractionation (CRYSTAF) using a CRYSTAF 200 unit commercially availablefrom PolymerChar, Valencia, Spain. The samples are dissolved in 1,2,4trichlorobenzene at 160° C. (0.66 mg/mL) for 1 hr and stabilized at 95°C. for 45 minutes. The sampling temperatures range from 95 to 30° C. ata cooling rate of 0.2° C./min. An infrared detector is used to measurethe polymer solution concentrations. The cumulative solubleconcentration is measured as the polymer crystallizes while thetemperature is decreased. The analytical derivative of the cumulativeprofile reflects the short chain branching distribution of the polymer.

The CRYSTAF peak temperature and area are identified by the peakanalysis module included in the CRYSTAF Software (Version 2001. b,PolymerChar, Valencia, Spain). The CRYSTAF peak finding routineidentifies a peak temperature as a maximum in the dW/dT curve and thearea between the largest positive inflections on either side of theidentified peak in the derivative curve. To calculate the CRYSTAF curve,the preferred processing parameters are with a temperature limit of 70°C. and with smoothing parameters above the temperature limit of 0.1, andbelow the temperature limit of 0.3.

DSC Standard Method (Excluding Samples 1-4 and A-C)

Differential Scanning Calorimetry results are determined using a TAImodel Q1000 DSC equipped with an RCS cooling accessory and anautosampler. A nitrogen purge gas flow of 50 m/min is used. The sampleis pressed into a thin film and melted in the press at about 175° C. andthen air-cooled to room temperature (25° C.). 3-10 mg of material isthen cut into a 6 mm diameter disk, accurately weighed, placed in alight aluminum pan (ca 50 mg), and then crimped shut. The thermalbehavior of the sample is investigated with the following temperatureprofile. The sample is rapidly heated to 180° C. and held isothermal for3 minutes in order to remove any previous thermal history. The sample isthen cooled to −40° C. at 10° C./min cooling rate and held at −40° C.for 3 minutes. The sample is then heated to 150° C. at 10° C./min.heating rate. The cooling and second heating curves are recorded.

The DSC melting peak is measured as the maximum in heat flow rate (W/g)with respect to the linear baseline drawn between −30° C. and end ofmelting. The heat of fusion is measured as the area under the meltingcurve between −30° C. and the end of melting using a linear baseline.

GPC Method (Excluding Samples 1-4 and A-C)

The gel permeation chromatographic system consists of either a PolymerLaboratories Model PL-210 or a Polymer Laboratories Model PL-220instrument. The column and carousel compartments are operated at 140° C.Three Polymer Laboratories 10-micron Mixed-B columns are used. Thesolvent is 1,2,4 trichlorobenzene. The samples are prepared at aconcentration of 0.1 grams of polymer in 50 milliliters of solventcontaining 200 ppm of butylated hydroxytoluene (BHT). Samples areprepared by agitating lightly for 2 hours at 160° C. The injectionvolume used is 100 microliters and the flow rate is 1.0 ml/minute.

Calibration of the GPC column set is performed with 21 narrow molecularweight distribution polystyrene standards with molecular weights rangingfrom 580 to 8,400,000, arranged in 6 “cocktail” mixtures with at least adecade of separation between individual molecular weights. The standardsare purchased from Polymer Laboratories (Shropshire, UK). Thepolystyrene standards are prepared at 0.025 grams in 50 milliliters ofsolvent for molecular weights equal to or greater than 1,000,000, and0.05 grams in 50 milliliters of solvent for molecular weights less than1,000,000. The polystyrene standards are dissolved at 80° C. with gentleagitation for 30 minutes. The narrow standards mixtures are run firstand in order of decreasing highest molecular weight component tominimize degradation. The polystyrene standard peak molecular weightsare converted to polyethylene molecular weights using the followingequation (as described in Williams and Ward, J. Polym. Sci., Polym.Let., 6, 621 (1968)): M_(polyethylene)=0.431(M_(polystyrene)).

Polyethylene equivalent molecular weight calculations are performedusing Viscotek TriSEC software Version 3.0.

Compression Set

Compression set is measured according to ASTM D 395. The sample isprepared by stacking 25.4 mm diameter round discs of 3.2 mm, 2.0 mm, and0.25 mm thickness until a total thickness of 12.7 mm is reached. Thediscs are cut from 12.7 cm×12.7 cm compression molded plaques moldedwith a hot press under the following conditions: zero pressure for 3 minat 190° C., followed by 86 MPa for 2 min at 190° C., followed by coolinginside the press with cold running water at 86 MPa.

Density

Samples for density measurement are prepared according to ASTM D 1928.Measurements are made within one hour of sample pressing using ASTMD792, Method B.

Flexural/Secant Modulus/Storage Modulus

Samples are compression molded using ASTM D 1928. Flexural and 2 percentsecant moduli are measured according to ASTM D-790. Storage modulus ismeasured according to ASTM D 5026-01 or equivalent technique.

Optical Properties

Films of 0.4 mm thickness are compression molded using a hot press(Carver Model #4095-4PR1001R). The pellets are placed betweenpolytetrafluoroethylene sheets, heated at 190° C. at 55 psi (380 kPa)for 3 min, followed by 1.3 MPa for 3 min, and then 2.6 MPa for 3 min.The film is then cooled in the press with running cold water at 1.3 MPafor 1 min. The compression molded films are used for opticalmeasurements, tensile behavior, recovery, and stress relaxation.

Clarity is measured using BYK Gardner Haze-gard as specified in ASTM D1746.

45° gloss is measured using BYK Gardner Glossmeter Microgloss 45° asspecified in ASTM D-2457

Internal haze is measured using BYK Gardner Haze-gard based on ASTM D1003 Procedure A. Mineral oil is applied to the film surface to removesurface scratches.

Mechanical Properties—Tensile, Hysteresis, and Tear

Stress-strain behavior in uniaxial tension is measured using ASTM D 1708microtensile specimens. Samples are stretched with an Instron at 500%min⁻¹ at 21° C. Tensile strength and elongation at break are reportedfrom an average of 5 specimens.

100% and 300% Hysteresis is determined from cyclic loading to 100% and300% strains using ASTM D 1708 microtensile specimens with an Instron™instrument. The sample is loaded and unloaded at 267% min⁻¹ for 3 cyclesat 21° C. Cyclic experiments at 300% and 80° C. are conducted using anenvironmental chamber. In the 80° C. experiment, the sample is allowedto equilibrate for 45 minutes at the test temperature before testing. Inthe 21° C., 300% strain cyclic experiment, the retractive stress at 150%strain from the first unloading cycle is recorded. Percent recovery forall experiments are calculated from the first unloading cycle using thestrain at which the load returned to the base line. The percent recoveryis defined as:

${\%\mspace{11mu}{Recovery}} = {\frac{ɛ_{f} - ɛ_{s}}{ɛ_{f}} \times 100}$where ε_(f) is the strain taken for cyclic loading and ε_(s) is thestrain where the load returns to the baseline during the 1^(st)unloading cycle.

Stress relaxation is measured at 50 percent strain and 37° C. for 12hours using an Instron™ instrument equipped with an environmentalchamber. The gauge geometry was 76 mm×25 mm×0.4 mm. After equilibratingat 37° C. for 45 min in the environmental chamber, the sample wasstretched to 50% strain at 333% min⁻¹ . Stress was recorded as afunction of time for 12 hours. The percent stress relaxation after 12hours was calculated using the formula:

${\%\mspace{11mu}{Stress}\mspace{14mu}{Relaxation}} = {\frac{L_{0} - L_{12}}{L_{0}} \times 100}$where L₀ is the load at 50% strain at 0 time and L₁₂ is the load at 50percent strain after 12 hours.

Tensile notched tear experiments are carried out on samples having adensity of 0.88 g/cc or less using an Instron™ instrument. The geometryconsists of a gauge section of 76 mm×13 mm×0.4 mm with a 2 mm notch cutinto the sample at half the specimen length. The sample is stretched at508 mm min⁻¹ at 21° C. until it breaks. The tear energy is calculated asthe area under the stress-elongation curve up to strain at maximum load.An average of at least 3 specimens are reported.

TMA

Thermal Mechanical Analysis (Penetration Temperature) is conducted on 30mm diameter×3.3 mm thick, compression molded discs, formed at 180° C.and 10 MPa molding pressure for 5 minutes and then air quenched. Theinstrument used is a TMA 7, brand available from Perkin-Elmer. In thetest, a probe with 1.5 mm radius tip (P/N N519-0416) is applied to thesurface of the sample disc with 1N force. The temperature is raised at5° C./min from 25° C. The probe penetration distance is measured as afunction of temperature. The experiment ends when the probe haspenetrated 1 mm into the sample.

DMA

Dynamic Mechanical Analysis (DMA) is measured on compression moldeddisks formed in a hot press at 180° C. at 10 MPa pressure for 5 minutesand then water cooled in the press at 90° C./min. Testing is conductedusing an ARES controlled strain rheometer (TA instruments) equipped withdual cantilever fixtures for torsion testing.

A 1.5 mm plaque is pressed and cut in a bar of dimensions 32×12 mm. Thesample is clamped at both ends between fixtures separated by 10 mm (gripseparation ΔL) and subjected to successive temperature steps from −100°C. to 200° C. (5° C. per step). At each temperature the torsion modulusG′ is measured at an angular frequency of 10 rad/s, the strain amplitudebeing maintained between 0.1 percent and 4 percent to ensure that thetorque is sufficient and that the measurement remains in the linearregime.

An initial static force of 10 g is maintained (auto-tension mode) toprevent slack in the sample when thermal expansion occurs. As aconsequence, the grip separation ΔL increases with the temperature,particularly above the melting or softening point of the polymer sample.The test stops at the maximum temperature or when the gap between thefixtures reaches 65 mm.

Melt Index

Melt index, or 12, is measured in accordance with ASTM D 1238, Condition190° C./2.16 kg. Melt index, or I₁₀ is also measured in accordance withASTM D 1238, Condition 190° C./10 kg.

ATREF

Analytical temperature rising elution fractionation (ATREF) analysis isconducted according to the method described in U.S. Pat. No. 4,798,081and Wilde, L.; Ryle, T. R.; Knobeloch, D. C.; Peat, I. R.; Determinationof Branching Distributions in Polyethylene and Ethylene Copolymers, J.Polyvn. Sci., 20, 441-455 (1982), which are incorporated by referenceherein in their entirety. The composition to be analyzed is dissolved intrichlorobenzene and allowed to crystallize in a column containing aninert support (stainless steel shot) by slowly reducing the temperatureto 20° C. at a cooling rate of 0.1° C./min. The column is equipped withan infrared detector. An ATREF chromatogram curve is then generated byeluting the crystallized polymer sample from the column by slowlyincreasing the temperature of the eluting solvent (trichlorobenzene)from 20 to 120° C. at a rate of 1.5° C./min.

¹³C NMR Analysis

The samples are prepared by adding approximately 3 g of a 50/50 mixtureof tetrachloroethane-d²/orthodichlorobenzene to 0.4 g sample in a 10 mmNMR tube. The samples are dissolved and homogenized by heating the tubeand its contents to 150° C. The data are collected using a JEOL ECLIPSE™400 MHz spectrometer or a Varian Unity PLUS™ 400 MHz spectrometer,corresponding to a ¹³C resonance frequency of 100.5 MHz. The data areacquired using 4000 transients per data file with a 6 second pulserepetition delay. To achieve minimum signal-to-noise for quantitativeanalysis, multiple data files are added together. The spectral width is25,000 Hz with a minimum file size of 32K data points. The samples areanalyzed at 130° C. in a 10 mm broad band probe. The comonomerincorporation is determined using Randall's triad method (Randall, J.C.; JMS-Rev. Macromol. Chem. Phys., C29, 201-317 (1989), which isincorporated by reference herein in its entirety.

Polymer Fractionation by TREF

Large-scale TREF fractionation is carried by dissolving 15-20 g ofpolymer in 2 liters of 1,2,4-trichlorobenzene (TCB)by stirring for 4hours at 160° C. The polymer solution is forced by 15 psig (100 kPa)nitrogen onto a 3 inch by 4 foot (7.6 cm×12 cm) steel column packed witha 60:40 (v:v) mix of 30-40 mesh (600-425 μm) spherical, technicalquality glass beads (available from Potters Industries, HC 30 Box 20,Brownwood, Tex., 76801) and stainless steel, 0.028″ (0.7 mm) diametercut wire shot (available from Pellets, Inc. 63 Industrial Drive, NorthTonawanda, N.Y., 14120). The column is immersed in a thermallycontrolled oil jacket, set initially to 160° C. The column is firstcooled ballistically to 125° C., then slow cooled to 20° C. at 0.04° C.per minute and held for one hour. Fresh TCB is introduced at about 65ml/min while the temperature is increased at 0.167° C. per minute.

Approximately 2000 ml portions of eluant from the preparative TREFcolumn are collected in a 16 station, heated fraction collector. Thepolymer is concentrated in each fraction using a rotary evaporator untilabout 50 to 100 ml of the polymer solution remains. The concentratedsolutions are allowed to stand overnight before adding excess methanol,filtering, and rinsing (approx. 300-500 ml of methanol including thefinal rinse). The filtration step is performed on a 3 position vacuumassisted filtering station using 5.0 μm polytetrafluoroethylene coatedfilter paper (available from Osmonics Inc., Cat# Z50WP04750). Thefiltrated fractions are dried overnight in a vacuum oven at 60° C. andweighed on an analytical balance before further testing.

Melt Strength

Melt Strength (MS) is measured by using a capillary rheometer fittedwith a 2.1 mm diameter, 20:1 die with an entrance angle of approximately45 degrees. After equilibrating the samples at 190° C. for 10 minutes,the piston is run at a speed of 1 inch/minute (2.54 cm/minute). Thestandard test temperature is 190° C. The sample is drawn uniaxially to aset of accelerating nips located 100 mm below the die with anacceleration of 2.4 mm/sec². The required tensile force is recorded as afunction of the take-up speed of the nip rolls. The maximum tensileforce attained during the test is defined as the melt strength. In thecase of polymer melt exhibiting draw resonance, the tensile force beforethe onset of draw resonance was taken as melt strength. The meltstrength is recorded in centiNewtons (“cN”).

Catalysts

The term “overnight”, if used, refers to a time of approximately 16-18hours, the term “room temperature”, refers to a temperature of 20-25°C., and the term “mixed alkanes” refers to a commercially obtainedmixture of C₆₋₉ aliphatic hydrocarbons available under the tradedesignation Isopar E®, from ExxonMobil Chemical Company. In the eventthe name of a compound herein does not conform to the structuralrepresentation thereof, the structural representation shall control. Thesynthesis of all metal complexes and the preparation of all screeningexperiments were carried out in a dry nitrogen atmosphere using dry boxtechniques. All solvents used were HPLC grade and were dried beforetheir use.

MMAO refers to modified methylalumoxane, a triisobutylaluminum modifiedmethylalumoxane available commercially from Akzo-Noble Corporation.

The preparation of catalyst (B1) is conducted as follows.

a) Preparation of(1-methylethyl)(2-hydroxy-3,5-di(t-butyl)phenyl)methylimine

3,5-Di-t-butylsalicylaldehyde (3.00 g) is added to 10 mL ofisopropylamine. The solution rapidly turns bright yellow. After stirringat ambient temperature for 3 hours, volatiles are removed under vacuumto yield a bright yellow, crystalline solid (97 percent yield).

b) Preparation of1,2-bis-(3,5-di-t-butylphenylene)(1-(N-(1-methylethyl)immino)methyl)(2-oxoyl)zirconiumdibenzyl

A solution of (1-methylethyl)(2-hydroxy-3,5-di(t-butyl)phenyl)imine (605mg, 2.2 mmol) in 5 mL toluene is slowly added to a solution ofZr(CH₂Ph)₄ (500 mg, 1.1 mmol) in 50 mL toluene. The resulting darkyellow solution is stirred for 30 min. Solvent is removed under reducedpressure to yield the desired product as a reddish-brown solid.

The preparation of catalyst (B2) is conducted as follows.

a) Preparation of (1-(2-methylcyclohexyl)ethyl)(2-oxoyl-3,5-di(t-butyl)phenyl)imine

2-Methylcyclohexylamine (8.44 mL, 64.0 mmol) is dissolved in methanol(90 mL), and di-t-butylsalicaldehyde (10.00 g, 42.67 mmol) is added. Thereaction mixture is stirred for three hours and then cooled to −25° C.for 12 hrs. The resulting yellow solid precipitate is collected byfiltration and washed with cold methanol (2×15 mL), and then dried underreduced pressure. The yield is 11.17 g of a yellow solid. ¹H NMR isconsistent with the desired product as a mixture of isomers.

b) Preparation ofbis-(1-(2-methylcyclohexyl)ethyl)(2-oxovl-3,5-di(t-butyl)phenyl)immino)zirconiumdibenzyl

A solution of(1-(2-methylcyclohexyl)ethyl)(2-oxoyl-3,5-di(t-butyl)phenyl)imine (7.63g, 23.2 mmol) in 200 mL toluene is slowly added to a solution ofZr(CH₂Ph)₄ (5.28 g, 11.6 mmol) in 600 mL toluene. The resulting darkyellow solution is stirred for 1 hour at 25° C. The solution is dilutedfurther with 680 mL toluene to give a solution having a concentration of0.00783 M.

Cocatalyst 1 A mixture of methyldi(C₁₄₋₁₈ alkyl)ammonium salts oftetrakis(pentafluorophenyl)borate (here-in-after armeenium borate),prepared by reaction of a long chain trialkylamine (Armeen™ M2HT,available from Akzo-Nobel, Inc.), HCl and Li[B(C₆F₅)₄], substantially asdisclosed in U.S. Pat. No. 5,919,9883, Ex. 2.

Cocatalyst 2 Mixed C₁₄₋₁₈ alkyldimethylammonium salt ofbis(tris(pentafluorophenyl)-alumane)-2-undecylimidazolide, preparedaccording to U.S. Pat. No. 6,395,671, Ex. 16.

Shuttling Agents The shuttling agents employed include diethylzinc (DEZ,SA1), di(i-butyl)zinc (SA2), di(n-hexyl)zinc (SA3), triethylaluminum(TEA, SA4), trioctylaluminum (SA5), triethylgallium (SA6),i-butylaluminum bis(dimethyl(t-butyl)siloxane) (SA7), i-butylaluminumbis(di(trimethylsilyl)amide) (SA8), n-octylaluminumdi(pyridine-2-methoxide) (SA9), bis(n-octadecyl)i-butylaluminum (SA10),i-butylaluminum bis(di(n-pentyl)amide) (SA11), n-octylaluminumbis(2,6-di-t-butylphenoxide) (SA12), n-octylaluminumdi(ethyl(1-naphthyl)amide) (SA13), ethylaluminumbis(t-butyldimethylsiloxide) (SA14), ethylaluminumdi(bis(trimethylsilyl)amide) (SA15), ethylaluminumbis(2,3,6,7-dibenzo-1-azacycloheptaneamide) (SA16), n-octylaluminumbis(2,3,6,7-dibenzo-1-azacycloheptaneamide) (SA17), n-octylaluminumbis(dimethyl(t-butyl)siloxide(SA18), ethylzinc (2,6-diphenylphenoxide)(SA19), and ethylzinc (t-butoxide) (SA20).

Examples 1-4, Comparative A-C

General High Throughput Parallel Polymerization Conditions

Polymerizations are conducted using a high throughput, parallelpolymerization reactor (PPR) available from Symyx technologies, Inc. andoperated substantially according to U.S. Pat. Nos. 6,248,540, 6,030,917,6,362,309, 6,306,658, and 6,316,663. Ethylene copolymerizations areconducted at 130° C. and 200 psi (1.4 MPa) with ethylene on demand using1.2 equivalents of cocatalyst 1 based on total catalyst used (1.1equivalents when MMAO is present). A series of polymerizations areconducted in a parallel pressure reactor (PPR) contained of 48individual reactor cells in a 6×8 array that are fitted with apre-weighed glass tube. The working volume in each reactor cell is 6000μL. Each cell is temperature and pressure controlled with stirringprovided by individual stirring paddles. The monomer gas and quench gasare plumbed directly into the PPR unit and controlled by automaticvalves. Liquid reagents are robotically added to each reactor cell bysyringes and the reservoir solvent is mixed alkanes. The order ofaddition is mixed alkanes solvent (4 ml), ethylene, 1-octene comonomer(1 ml), cocatalyst 1 or cocatalyst 1/MMAO mixture, shuttling agent, andcatalyst or catalyst mixture. When a mixture of cocatalyst 1 and MMAO ora mixture of two catalysts is used, the reagents are premixed in a smallvial immediately prior to addition to the reactor. When a reagent isomitted in an experiment, the above order of addition is otherwisemaintained. Polymerizations are conducted for approximately 1-2 minutes,until predetermined ethylene consumptions are reached. After quenchingwith CO, the reactors are cooled and the glass tubes are unloaded. Thetubes are transferred to a centrifuge/vacuum drying unit, and dried for12 hours at 60° C. The tubes containing dried polymer are weighed andthe difference between this weight and the tare weight gives the netyield of polymer. Results are contained in Table 1. In Table 1 andelsewhere in the application, comparative compounds are indicated by anasterisk (*).

Examples 1-4 demonstrate the synthesis of linear block copolymers by thepresent invention as evidenced by the formation of a very narrow MWD,essentially monomodal copolymer when DEZ is present and a bimodal, broadmolecular weight distribution product (a mixture of separately producedpolymers) in the absence of DEZ. Due to the fact that Catalyst (A1) isknown to incorporate more octene than Catalyst (B1), the differentblocks or segments of the resulting copolymers of the invention aredistinguishable based on branching or density.

TABLE 1 Cat. (A1) Cat (B1) Cocat MMAO shuttling Ex. (μmol) (μmol) (μmol)(μmol) agent (μmol) Yield (g) Mn Mw/Mn hexyls¹ A* 0.06 — 0.066 0.3 —0.1363 300502 3.32 — B* — 0.1 0.110 0.5 — 0.1581 36957 1.22 2.5 C* 0.060.1 0.176 0.8 — 0.2038 45526  5.30² 5.5 1 0.06 0.1 0.192 — DEZ (8.0)0.1974 28715 1.19 4.8 2 0.06 0.1 0.192 — DEZ (80.0) 0.1468 2161 1.1214.4 3 0.06 0.1 0.192 — TEA (8.0) 0.208 22675 1.71 4.6 4 0.06 0.1 0.192— TEA (80.0) 0.1879 3338 1.54 9.4 ¹C₆ or higher chain content per 1000carbons ²Bimodal molecular weight distribution

It may be seen the polymers produced according to the invention have arelatively narrow polydispersity (Mw/Mn) and larger block-copolymercontent (trimer, tetramer, or larger) than polymers prepared in theabsence of the shuttling agent.

Further characterizing data for the polymers of Table 1 are determinedby reference to the figures. More specifically DSC and ATREF resultsshow the following:

The DSC curve for the polymer of Example 1 shows a 115.7° C. meltingpoint (Tm) with a heat of fusion of 158.1 J/g. The corresponding CRYSTAFcurve shows the tallest peak at 34.5° C. with a peak area of 52.9percent. The difference between the DSC Tm and the Tcrystaf is 81.2° C.

The DSC curve for the polymer of Example 2 shows a peak with a 109.7° C.melting point (Tm) with a heat of fusion of 214.0 J/g. The correspondingCRYSTAF curve shows the tallest peak at 46.2° C. with a peak area of57.0 percent. The difference between the DSC Tm and the Tcrystaf is63.5° C.

The DSC curve for the polymer of Example 3 shows a peak with a 120.7° C.melting point (Tm) with a heat of fusion of 160.1 J/g. The correspondingCRYSTAF curve shows the tallest peak at 66.1° C. with a peak area of71.8 percent. The difference between the DSC Tm and the Tcrystaf is54.6° C.

The DSC curve for the polymer of Example 4 shows a peak with a 104.5° C.melting point (Tm) with a heat of fusion of 170.7 J/g. The correspondingCRYSTAF curve shows the tallest peak at 30° C. with a peak area of 18.2percent. The difference between the DSC Tm and the Tcrystaf is 74.5° C.

The DSC curve for Comparative Example A* shows a 90.0° C. melting point(Tm) with a heat of fusion of 86.7 J/g. The corresponding CRYSTAF curveshows the tallest peak at 48.5° C. with a peak area of 29.4 percent.Both of these values are consistent with a resin that is low in density.The difference between the DSC Tm and the Tcrystaf is 41.8° C.

The DSC curve for Comparative Example B* shows a 129.8° C. melting point(Tm) with a heat of fusion of 237.0 J/g. The corresponding CRYSTAF curveshows the tallest peak at 82.4° C. with a peak area of 83.7 percent.Both of these values are consistent with a resin that is high indensity. The difference between the DSC Tm and the Tcrystaf is 47.4° C.

The DSC curve for Comparative Example C* shows a 125.3° C. melting point(Tm) with a heat of fusion of 143.0 J/g. The corresponding CRYSTAF curveshows the tallest peak at 81.8° C. with a peak area of 34.7 percent aswell as a lower crystalline peak at 52.4° C. The separation between thetwo peaks is consistent with the presence of a high crystalline and alow crystalline polymer. The difference between the DSC Tm and theTcrystaf is 43.5° C.

Examples 5-19, Comparative Examples D*-F*, Continuous SolutionPolymerization, Catalyst A1/B2+DEZ

Continuous solution polymerizations are carried out in a computercontrolled autoclave reactor equipped with an internal stirrer. Purifiedmixed alkanes solvent (ISOPAR™ E available from ExxonMobil ChemicalCompany), ethylene at 2.70 lbs/hour (1.22 kg/hour), 1-octene, andhydrogen (where used) are supplied to a 3.8 L reactor equipped with ajacket for temperature control and an internal thermocouple. The solventfeed to the reactor is measured by a mass-flow controller. A variablespeed diaphragm pump controls the solvent flow rate and pressure to thereactor. At the discharge of the pump, a side stream is taken to provideflush flows for the catalyst and cocatalyst 1 injection lines and thereactor agitator. These flows are measured by Micro-Motion mass flowmeters and controlled by control valves or by the manual adjustment ofneedle valves. The remaining solvent is combined with 1-octene,ethylene, and hydrogen (where used) and fed to the reactor. A mass flowcontroller is used to deliver hydrogen to the reactor as needed. Thetemperature of the solvent/monomer solution is controlled by use of aheat exchanger before entering the reactor. This stream enters thebottom of the reactor. The catalyst component solutions are meteredusing pumps and mass flow meters and are combined with the catalystflush solvent and introduced into the bottom of the reactor. The reactoris run liquid-full at 500 psig (3.45 MPa) with vigorous stirring.Product is removed through exit lines at the top of the reactor. Allexit lines from the reactor are steam traced and insulated.Polymerization is stopped by the addition of a small amount of waterinto the exit line along with any stabilizers or other additives andpassing the mixture through a static mixer. The product stream is thenheated by passing through a heat exchanger before devolatilization. Thepolymer product is recovered by extrusion using a devolatilizingextruder and water cooled pelletizer. Process details and results arecontained in Table 2. Selected polymer properties are provided in Table3.

TABLE 2 Process details for preparation of exemplary polymers Cat Cat A1Cat B2 DEZ Cocat Cocat Poly C₈H₁₆ Solv. H₂ A1² Flow B2³ Flow DEZ FlowConc. Flow [C₂H₄]/ Rate⁵ Conv Ex. kg/hr kg/hr sccm¹ T ° C. ppm kg/hr ppmkg/hr Conc % kg/hr ppm kg/hr [DEZ]⁴ kg/hr %⁶ Solids % Eff.⁷ D* 1.63 12.729.90 120 142.2 0.14 — — 0.19 0.32  820 0.17 536 1.81 88.8 11.2 95.2 E*″  9.5 5.00 ″ — — 109 0.10 0.19 ″ 1743 0.40 485 1.47 89.9 11.3 126.8 F*″ 11.3 251.6 ″ 71.7 0.06 30.8 0.06 — — ″ 0.11 — 1.55 88.5 10.3 257.7  5″ ″ — ″ ″ 0.14 30.8 0.13 0.17 0.43 ″ 0.26 419 1.64 89.6 11.1 118.3  6 ″″ 4.92 ″ ″ 0.10 30.4 0.08 0.17 0.32 ″ 0.18 570 1.65 89.3 11.1 172.7  7 ″″ 21.70 ″ ″ 0.07 30.8 0.06 0.17 0.25 ″ 0.13 718 1.60 89.2 10.6 244.1  8″ ″ 36.90 ″ ″ 0.06 ″ ″ ″ 0.10 ″ 0.12 1778 1.62 90.0 10.8 261.1  9 ″ ″78.43 ″ ″ ″ ″ ″ ″ 0.04 ″ ″ 4596 1.63 90.2 10.8 267.9 10 ″ ″ 0.00 12371.1 0.12 30.3 0.14 0.34 0.19 1743 0.08 415 1.67 90.31 11.1 131.1 11 ″ ″″ 120 71.1 0.16 ″ 0.17 0.80 0.15 1743 0.10 249 1.68 89.56 11.1 100.6 12″ ″ ″ 121 71.1 0.15 ″ 0.07 ″ 0.09 1743 0.07 396 1.70 90.02 11.3 137.0 13″ ″ ″ 122 71.1 0.12 ″ 0.06 ″ 0.05 1743 0.05 653 1.69 89.64 11.2 161.9 14″ ″ ″ 120 71.1 0.05 ″ 0.29 ″ 0.10 1743 0.10 395 1.41 89.42 9.3 114.1 152.45 ″ ″ ″ 71.1 0.14 ″ 0.17 ″ 0.14 1743 0.09 282 1.80 89.33 11.3 121.316 ″ ″ ″ 122 71.1 0.10 ″ 0.13 ″ 0.07 1743 0.07 485 1.78 90.11 11.2 159.717 ″ ″ ″ 121 71.1 0.10 ″ 0.14 ″ 0.08 1743 ″ 506 1.75 89.08 11.0 155.6 180.69 ″ ″ 121 71.1 ″ ″ 0.22 ″ 0.11 1743 0.10 331 1.25 89.93 8.8 90.2 190.32 ″ ″ 122 71.1 0.06 ″ ″ ″ 0.09 1743 0.08 367 1.16 90.74 8.4 106.0*Comparative Example, not an example of the invention ¹standard cm³/min²[N-(2,6-di(1-methylethyl)phenyl)amido)(2-isopropylphenyl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafniumdimethyl³bis-(1-(2-methylcyclohexyl)ethyl)(2-oxoyl-3,5-di(t-butyl)phenyl)immino)zirconium dibenzyl ⁴molar ratio in reactor ⁵polymer production rate⁶percent ethylene conversion in reactor ⁷efficiency, kg polymer/g Mwhere g M = g Hf + g Zr

TABLE 3 Properties of exemplary polymers Heat of CRYSTAF Density Mw MnFusion T_(m) T_(c) T_(CRYSTAF) Tm − T_(CRYSTAF) Peak Area Ex. (g/cm³) I₂I₁₀ I₁₀/I₂ (g/mol) (g/mol) Mw/Mn (J/g) (° C.) (° C.) (° C.) (° C.)(percent) D* 0.8627 1.5 10.0 6.5 110,000 55,800 2.0 32 37 45 30 7 99 E*0.9378 7.0 39.0 5.6 65,000 33,300 2.0 183 124 113 79 45 95 F* 0.8895 0.912.5 13.4 137,300 9,980 13.8 90 125 111 78 47 20  5 0.8786 1.5 9.8 6.7104,600 53,200 2.0 55 120 101 48 72 60  6 0.8785 1.1 7.5 6.5 10960053300 2.1 55 115 94 44 71 63  7 0.8825 1.0 7.2 7.1 118,500 53,100 2.2 69121 103 49 72 29  8 0.8828 0.9 6.8 7.7 129,000 40,100 3.2 68 124 106 8043 13  9 0.8836 1.1 9.7 9.1 129600 28700 4.5 74 125 109 81 44 16 100.8784 1.2 7.5 6.5 113,100 58,200 1.9 54 116 92 41 75 52 11 0.8818 9.159.2 6.5 66,200 36,500 1.8 63 114 93 40 74 25 12 0.8700 2.1 13.2 6.4101,500 55,100 1.8 40 113 80 30 83 91 13 0.8718 0.7 4.4 6.5 132,10063,600 2.1 42 114 80 30 81 8 14 0.9116 2.6 15.6 6.0 81,900 43,600 1.9123 121 106 73 48 92 15 0.8719 6.0 41.6 6.9 79,900 40,100 2.0 33 114 9132 82 10 16 0.8758 0.5 3.4 7.1 148,500 74,900 2.0 43 117 96 48 69 65 170.8757 1.7 11.3 6.8 107,500 54,000 2.0 43 116 96 43 73 57 18 0.9192 4.124.9 6.1 72,000 37,900 1.9 136 120 106 70 50 94 19 0.9344 3.4 20.3 6.076,800 39,400 1.9 169 125 112 80 45 88 *Comparative Example, not anexample of the invention

The resulting polymers are tested by DSC and ATREF as with previousexamples. Results are as follows:

The DSC curve for the polymer of Example 5 shows a peak with a 119.6° C.melting point (Tm) with a heat of fusion of 60.0 J/g. The correspondingCRYSTAF curve shows the tallest peak at 47.6° C. with a peak area of59.5 percent. The delta between the DSC Tm and the Tcrystaf is 72.0° C.

The DSC curve for the polymer of Example 6 shows a peak with a 115.2° C.melting point (Tm) with a heat of fusion of 60.4 J/g. The correspondingCRYSTAF curve shows the tallest peak at 44.2° C. with a peak area of62.7 percent. The delta between the DSC Tm and the Tcrystaf is 71.0° C.

The DSC curve for the polymer of Example 7 shows a peak with a 121.3° C.melting point with a heat of fusion of 69.1 J/g. The correspondingCRYSTAF curve shows the tallest peak at 49.2° C. with a peak area of29.4 percent. The delta between the DSC Tm and the Tcrystaf is 72.1° C.

The DSC curve for the polymer of Example 8 shows a peak with a 123.5° C.melting point (Tm) with a heat of fusion of 67.9 J/g. The correspondingCRYSTAF curve shows the tallest peak at 80.1° C. with a peak area of12.7 percent. The delta between the DSC Tm and the Tcrystaf is 43.4° C.

The DSC curve for the polymer of Example 9 shows a peak with a 124.6° C.melting point (Tm) with a heat of fusion of 73.5 J/g. The correspondingCRYSTAF curve shows the tallest peak at 80.8° C. with a peak area of16.0 percent. The delta between the DSC Tm and the Tcrystaf is 43.8° C.

The DSC curve for the polymer of Example 10 shows a peak with a 115.6°C. melting point (Tm) with a heat of fusion of 60.7 J/g. Thecorresponding CRYSTAF curve shows the tallest peak at 40.9° C. with apeak area of 52.4 percent. The delta between the DSC Tm and the Tcrystafis 74.7° C.

The DSC curve for the polymer of Example 11 shows a peak with a 113.6°C. melting point (Tm) with a heat of fusion of 70.4 J/g. Thecorresponding CRYSTAF curve shows the tallest peak at 39.6° C. with apeak area of 25.2 percent. The delta between the DSC Tm and the Tcrystafis 74.1° C.

The DSC curve for the polymer of Example 12 shows a peak with a 113.2°C. melting point (Tm) with a heat of fusion of 48.9 J/g. Thecorresponding CRYSTAF curve shows no peak equal to or above 30° C.(Tcrystaf for purposes of further calculation is therefore set at 30°C.). The delta between the DSC Tm and the Tcrystaf is 83.2° C.

The DSC curve for the polymer of Example 13 shows a peak with a 114.4°C. melting point (Tm) with a heat of fusion of 49.4 J/g. Thecorresponding CRYSTAF curve shows the tallest peak at 33.8° C. with apeak area of 7.7 percent. The delta between the DSC Tm and the Tcrystafis 84.4° C.

The DSC for the polymer of Example 14 shows a peak with a 120.8° C.melting point (Tm) with a heat of fusion of 127.9 J/g. The correspondingCRYSTAF curve shows the tallest peak at 72.9° C. with a peak area of92.2 percent. The delta between the DSC Tm and the Tcrystaf is 47.9° C.

The DSC curve for the polymer of Example 15 shows a peak with a 114.3°C. melting point (Tm) with a heat of fusion of 36.2 J/g. Thecorresponding CRYSTAF curve shows the tallest peak at 32.3° C. with apeak area of 9.8 percent. The delta between the DSC Tm and the Tcrystafis 82.0° C.

The DSC curve for the polymer of Example 16 shows a peak with a 116.6°C. melting point (Tm) with a heat of fusion of 44.9 J/g. Thecorresponding CRYSTAF curve shows the tallest peak at 48.0° C. with apeak area of 65.0 percent. The delta between the DSC Tm and the Tcrystafis 68.6° C.

The DSC curve for the polymer of Example 17 shows a peak with a 116.0°C. melting point (Tm) with a heat of fusion of 47.0 J/g. Thecorresponding CRYSTAF curve shows the tallest peak at 43.1° C. with apeak area of 56.8 percent. The delta between the DSC Tm and the Tcrystafis 72.9° C.

The DSC curve for the polymer of Example 18 shows a peak with a 120.5°C. melting point (Tm) with a heat of fusion of 141.8 J/g. Thecorresponding CRYSTAF curve shows the tallest peak at 70.0° C. with apeak area of 94.0 percent. The delta between the DSC Tm and the Tcrystafis 50.5° C.

The DSC curve for the polymer of Example 19 shows a peak with a 124.8°C. melting point (Tm) with a heat of fusion of 174.8 J/g. Thecorresponding CRYSTAF curve shows the tallest peak at 79.9° C. with apeak area of 87.9 percent. The delta between the DSC Tm and the Tcrystafis 45.0° C.

The DSC curve for the polymer of Comparative Example D* shows a peakwith a 37.3° C. melting point (Tm) with a heat of fusion of 31.6 J/g.The corresponding CRYSTAF curve shows no peak equal to and above 30° C.Both of these values are consistent with a resin that is low in density.The delta between the DSC Tm and the Tcrystaf is 7.3° C.

The DSC curve for the polymer of Comparative Example E* shows a peakwith a 124.0° C. melting point (Tm) with a heat of fusion of 179.3 J/g.The corresponding CRYSTAF curve shows the tallest peak at 79.3° C. witha peak area of 94.6 percent. Both of these values are consistent with aresin that is high in density. The delta between the DSC Tm and theTcrystaf is 44.6° C.

The DSC curve for the polymer of Comparative Example F* shows a peakwith a 124.8° C. melting point (Tm) with a heat of fusion of 90.4 J/g.The corresponding CRYSTAF curve shows the tallest peak at 77.6° C. witha peak area of 19.5 percent. The separation between the two peaks isconsistent with the presence of both a high crystalline and a lowcrystalline polymer. The delta between the DSC Tm and the Tcrystaf is47.2° C.

Physical Property Testing

Polymer samples are evaluated for physical properties such as hightemperature resistance properties, as evidenced by TMA temperaturetesting, pellet blocking strength, high temperature recovery, hightemperature compression set and storage modulus ratio, G′(25°C.)/G′(100° C.). Several commercially available polymers are included inthe tests: Comparative G* is a substantially linear ethylene/l-octenecopolymer (AFFINITY®, available from The Dow Chemical Company),Comparative H* is an elastomeric, substantially linear ethylene/1-octenecopolymer (AFFINITY®EG8100, available from The Dow Chemical Company),Comparative Example I* is a substantially linear ethylene/1-octenecopolymer (AFFINITY®PL1840, available from The Dow Chemical Company),Comparative Example J* is a hydrogenated styrene/butadiene/styrenetriblock copolymer (KRATON™ G1652, available from KRATON Polymers),Comparative Example K* is a thermoplastic vulcanizate (TPV, a polyolefinblend containing dispersed therein a crosslinked elastomer). Results arepresented in Table 4.

TABLE 4 High Temperature Mechanical Properties TMA-1 mm Pellet Blocking300% Strain Compression penetration Strength G′(25° C.)/ Recovery (80°C.) Set (70° C.) Ex. (° C.) lb/ft² (kPa) G′(100° C.) (percent) (percent)D* 51 — 9 Failed — E* 130 — 18 — — F* 70 141 (6.8) 9 Failed 100  5 104 0 (0) 6 81 49  6 110 — 5 — 52  7 113 — 4 84 43  8 111 — 4 Failed 41  997 — 4 — 66 10 108 — 5 81 55 11 100 — 8 — 68 12 88 — 8 — 79 13 95 — 6 8471 14 125 — 7 — — 15 96 — 5 — 58 16 113 — 4 — 42 17 108  0 (0) 4 82 4718 125 — 10 — — 19 133 — 9 — — G* 75 463 (22.2) 89 Failed 100 H* 70 213(10.2) 29 Failed 100 I* 111 — 11 — — J* 107 — 5 Failed 100 K* 152 — 3 —40

In Table 4, Comparative Example F* (which is a physical blend of the twopolymers resulting from simultaneous polymerizations using catalyst A1and B1) has a 1 mm penetration temperature of about 70° C., whileExamples 5-9 have a 1 mm penetration temperature of 100° C. or greater.Further, examples 10-19 all have a 1 mm penetration temperature ofgreater than 85° C., with most having 1 mm TMA temperature of greaterthan 90° C. or even greater than 100° C. This shows that the novelpolymers have better dimensional stability at higher temperaturescompared to a physical blend. Comparative Example J* (a commercial SEBS)has a good 1 mm TMA temperature of about 107° C., but it has very poor(high temperature 70° C.) compression set of about 100 percent and italso failed to recover (sample broke) during a high temperature (80° C.)300 percent strain recovery. Thus the exemplified polymers have a uniquecombination of properties unavailable even in some commerciallyavailable, high performance thermoplastic elastomers.

Similarly, Table 4 shows a low (good) storage modulus ratio, G′(25°C.)/G′(100° C.), for the inventive polymers of 6 or less, whereas aphysical blend (Comparative Example F*) has a storage modulus ratio of 9and a random ethylene/octene copolymer (Comparative Example G*) ofsimilar density has a storage modulus ratio an order of magnitudegreater (89). It is desirable that the storage modulus ratio of apolymer be as close to 1 as possible. Such polymers will be relativelyunaffected by temperature, and fabricated articles made from suchpolymers can be usefully employed over a broad temperature range. Thisfeature of low storage modulus ratio and temperature independence isparticularly useful in elastomer applications such as in pressuresensitive adhesive formulations.

The data in Table 4 also demonstrate that the polymers of the inventionpossess improved pellet blocking strength. In particular, Example 5 hasa pellet blocking strength of 0 MPa, meaning it is free flowing underthe conditions tested, compared to Comparative Examples F* and G* whichshow considerable blocking. Blocking strength is important since bulkshipment of polymers having large blocking strengths can result inproduct clumping or sticking together upon storage or shipping,resulting in poor handling properties.

High temperature (70° C.) compression set for the inventive polymers isgenerally good, meaning generally less than about 80 percent, preferablyless than about 70 percent and especially less than about 60 percent. Incontrast, Comparative Examples F*, G*, H* and J* all have a 70° C.compression set of 100 percent (the maximum possible value, indicatingno recovery). Good high temperature compression set (low numericalvalues) is especially needed for applications such as gaskets, windowprofiles, o-rings, and the like.

TABLE 5 Ambient Temperature Mechanical Properties Tensile 100%Retractive Flex Tensile Abrasion: Notched Strain 300% Strain Stress atCompres- Stress Modu- Modu- Tensile Elongation Tensile Elongation VolumeTear Recovery Recovery 150% sion Relaxation lus lus Strength at Break¹Strength at Break Loss Strength 21° C. 21° C. Strain Set 21° C. at 50%Ex. (MPa) (MPa) (MPa)¹ (%) (MPa) (%) (mm³) (mJ) (percent) (percent)(kPa) (Percent) Strain² D* 12 5 — — 10 1074 — — 91 83 760 — — E* 895 589— 31 1029 — — — — — — — F* 57 46 — — 12 824 93 339 78 65 400 42 —  5 3024 14 951 16 1116 48 — 87 74 790 14 33  6 33 29 — — 14 938 — — — 75 86113 —  7 44 37 15 846 14 854 39 — 82 73 810 20 —  8 41 35 13 785 14 81045 461 82 74 760 22 —  9 43 38 — — 12 823 — — — — — 25 — 10 23 23 — — 14902 — — 86 75 860 12 — 11 30 26 — — 16 1090 — 976 89 66 510 14 30 12 2017 12 961 13 931 — 1247 91 75 700 17 — 13 16 14 — — 13 814 — 691 91 — —21 — 14 212 160 — — 29 857 — — — — — — — 15 18 14 12 1127  10 1573 —2074 89 83 770 14 — 16 23 20 — — 12 968 — — 88 83 1040 13 — 17 20 18 — —13 1252 — 1274 13 83 920  4 — 18 323 239 — — 30 808 — — — — — — — 19 706483 — — 36 871 — — — — — — — G* 15 15 — — 17 1000 — 746 86 53 110 27 50H* 16 15 — — 15 829 — 569 87 60 380 23 — I* 210 147 — — 29 697 — — — — —— — J* — — — — 32 609 — — 93 96 1900 25 — K* — — — — — — — — — — — 30 —¹Tested at 51 cm/minute ²measured at 38° C. for 12 hours

Table 5 shows results for mechanical properties for the new polymers aswell as for various comparison polymers at ambient temperatures. It maybe seen that the inventive polymers have very good abrasion resistancewhen tested according to ISO 4649, generally showing a volume loss ofless than about 90 mm₃, preferably less than about 80 mm³, andespecially less than about 50 mm³. In this test, higher numbers indicatehigher volume loss and consequently lower abrasion resistance.

Tear strength as measured by tensile notched tear strength of theinventive polymers is generally 1000 mJ or higher, as shown in Table 5.Tear strength for the inventive polymers can be as high as 3000 mJ, oreven as high as 5000 mJ. Comparative polymers generally have tearstrengths no higher than 750 mJ.

Table 5 also shows that the polymers of the invention have betterretractive stress at 150 percent strain (demonstrated by higherretractive stress values) than some of the comparative samples.Comparative Examples F*, G* and H* have retractive stress value at 150percent strain of 400 kPa or less, while the inventive polymers haveretractive stress values at 150 percent strain of 500 kPa (Ex. 11) to ashigh as about 1100 kPa (Ex. 17). Polymers having higher than 150 percentretractive stress values would be quite useful for elastic applications,such as elastic fibers and fabrics, especially nonwoven fabrics. Otherapplications include diaper, hygiene, and medical garment waistbandapplications, such as tabs and elastic bands.

Table 5 also shows that stress relaxation (at 50 percent strain) is alsoimproved (less) for the inventive polymers as compared to, for example,Comparative Example G*. Lower stress relaxation means that the polymerretains its force better in applications such as diapers and othergarments where retention of elastic properties over long time periods atbody temperatures is desired.

Optical Testing

TABLE 6 Polymer Optical Properties Ex. Internal Haze (percent) Clarity(percent) 45° Gloss (percent) F* 84 22 49 G* 5 73 56  5 13 72 60  6 3369 53  7 28 57 59  8 20 65 62  9 61 38 49 10 15 73 67 11 13 69 67 12 875 72 13 7 74 69 14 59 15 62 15 11 74 66 16 39 70 65 17 29 73 66 18 6122 60 19 74 11 52 G* 5 73 56 H* 12 76 59 I* 20 75 59

The optical properties reported in Table 6 are based on compressionmolded films substantially lacking in orientation. Optical properties ofthe polymers may be varied over wide ranges, due to variation incrystallite size, resulting from variation the quantity of chainshuttling agent employed in the polymerization.

Extractions of Multi-Block Copolymers

Extraction studies of the polymers of Examples 5, 7 and ComparativeExample E* are conducted. In the experiments, the polymer sample isweighed into a glass fitted extraction thimble and fitted into aKumagawa type extractor. The extractor with sample is purged withnitrogen, and a 500 mL round bottom flask is charged with 350 mL ofdiethyl ether. The flask is then fitted to the extractor. The ether isheated while being stirred. Time is noted when the ether begins tocondense into the thimble, and the extraction is allowed to proceedunder nitrogen for 24 hours. At this time, heating is stopped and thesolution is allowed to cool. Any ether remaining in the extractor isreturned to the flask. The ether in the flask is evaporated under vacuumat ambient temperature, and the resulting solids are purged dry withnitrogen. Any residue is transferred to a weighed bottle usingsuccessive washes of hexane. The combined hexane washes are thenevaporated with another nitrogen purge, and the residue dried undervacuum overnight at 40° C. Any remaining ether in the extractor ispurged dry with nitrogen.

A second clean round bottom flask charged with 350 mL of hexane is thenconnected to the extractor. The hexane is heated to reflux with stirringand maintained at reflux for 24 hours after hexane is first noticedcondensing into the thimble. Heating is then stopped and the flask isallowed to cool. Any hexane remaining in the extractor is transferredback to the flask. The hexane is removed by evaporation under vacuum atambient temperature, and any residue remaining in the flask istransferred to a weighed bottle using successive hexane washes. Thehexane in the flask is evaporated by a nitrogen purge, and the residueis vacuum dried overnight at 40° C.

The polymer sample remaining in the thimble after the extractions istransferred from the thimble to a weighed bottle and vacuum driedovernight at 40° C. Results are contained in Table 7.

TABLE 7 ether ether C₈ hexane hexane C₈ residue wt. soluble soluble molesoluble soluble mole C₈ mole Sample (g) (g) (percent) percent¹ (g)(percent) percent¹ percent¹ Comp. F* 1.097 0.063 5.69 12.2 0.245 22.3513.6 6.5 Ex. 5 1.006 0.041 4.08 — 0.040 3.98 14.2 11.6 Ex. 7 1.092 0.0171.59 13.3 0.012 1.10 11.7 9.9 ¹Determined by ¹³C NMRAdditional Polymer Examples 19 A-F, Continuous Solution Polymerization,Catalyst A1/B2+DEZ

Continuous solution polymerizations are carried out in a computercontrolled well-mixed reactor. Purified mixed alkanes solvent (ISOPAR™ Eavailable from ExxonMobil Chemical Company), ethylene, 1-octene, andhydrogen (where used) are combined and fed to a 27 gallon reactor. Thefeeds to the reactor are measured by mass-flow controllers. Thetemperature of the feed stream is controlled by use of a glycol cooledheat exchanger before entering the reactor. The catalyst componentsolutions are metered using pumps and mass flow meters. The reactor isrun liquid-full at approximately 550 psig pressure. Upon exiting thereactor, water and additive are injected in the polymer solution. Thewater hydrolyzes the catalysts, and terminates the polymerizationreactions. The post reactor solution is then heated in preparation for atwo-stage devolatization. The solvent and unreacted monomers are removedduring the devolatization process. The polymer melt is pumped to a diefor underwater pellet cutting.

Process details and results are contained in Table 8. Selected polymerproperties are provided in Table 9.

TABLE 8 Polymerization Conditions for Polymers 19a-j. Cat A1² Cat CatCat C₂H₄ C₈H₁₆ Solv. H₂ T Conc. A1 B2³ B2 DEZ DEZ Cocat 1 Ex. lb/hrlb/hr lb/hr sccm¹ ° C. ppm lb/hr ppm lb/hr wt % lb/hr ppm 19a 55.2932.03 323.03 101 120 600 0.25 200 0.42 3.0 0.70 4500 19b 53.95 28.96325.3  577 120 600 0.25 200 0.55 3.0 0.24 4500 19c 55.53 30.97 324.37550 120 600 0.216 200 0.609 3.0 0.69 4500 19d 54.83 30.58 326.33 60 120600 0.22 200 0.63 3.0 1.39 4500 19e 54.95 31.73 326.75 251 120 600 0.21200 0.61 3.0 1.04 4500 19f 50.43 34.80 330.33 124 120 600 0.20 200 0.603.0 0.74 4500 19g 50.25 33.08 325.61 188 120 600 0.19 200 0.59 3.0 0.544500 19h 50.15 34.87 318.17 58 120 600 0.21 200 0.66 3.0 0.70 4500 19i55.02 34.02 323.59 53 120 600 0.44 200 0.74 3.0 1.72 4500 19j  7.46 9.04 50.6 47 120 150 0.22 76.7 0.36 0.5 0.19 — Cocat 1 Cocat 2 Cocat 2[Zn]⁴ in Poly. Flow Conc. Flow polymer Rate⁵ Conv⁶ Polymer Ex. lb/hr ppmlb/hr ppm lb/hr wt % wt % Eff.⁷ 19a 0.65 525 0.33 248 83.94 88.0 17.28297 19b 0.63 525 0.11  90 80.72 88.1 17.2  295 19c 0.61 525 0.33 24684.13 88.9 17.16 293 19d 0.66 525 0.66 491 82.56 88.1 17.07 280 19e 0.64525 0.49 368 84.11 88.4 17.43 288 19f 0.52 525 0.35 257 85.31 87.5 17.09319 19g 0.51 525 0.16 194 83.72 87.5 17.34 333 19h 0.52 525 0.70 25983.21 88.0 17.46 312 19i 0.70 525 1.65 600 86.63 88.0 17.6  275 19j — —— — — — — — ¹standard cm³/min²[N-(2,6-di(1-methylethyl)phenyl)amido)(2-isopropylphenyl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafniumdimethyl³bis-(1-(2-methylcyclohexyl)ethyl)(2-oxoyl-3,5-di(t-butyl)phenyl)immino)zirconium dimethyl ⁴ppm in final product calculated by mass balance⁵polymer production rate ⁶weight percent ethylene conversion in reactor⁷efficiency, kg polymer/g M where g M = g Hf + g Z

TABLE 9 Polymer Physical properties Heat of CRYSTAF Polymer Ex. DensityMw Mn Fusion T_(m) TCRYSTAF Tm − TCRYSTAF Peak Area No. (g/cc) I₂ I₁₀I₁₀/I₂ (g/mol) (g/mol) M_(w)/M_(n) (J/g) (° C.) T_(c) (° C.) (° C.) (°C.) (wt %) 19g 0.8649 0.9 6.4 7.1 135000 64800 2.1 26 120 92 30 90 9019h 0.8654 1.0 7.0 7.1 131600 66900 2.0 26 118 88 — — — 19k¹ 0.8652 1.17.5 6.8 124900 60700 2.1 27 119 88 30 89 89.3 19l¹ 0.892 1.1 7.7 6.893000 45500 2.0 84 120 101 — — — Note: ¹Polymer Examples 19k and 19lwere copolymers of ethylene and octene which were prepared substantiallysimilar to Examples 1-19 and Examples 19a-h and according to theconditions shown in Table 10 below.

TABLE 9A Average Block Index For exemplary polymers¹ Example Zn/C₂ ²Average BI Polymer F 0 0 Polymer 8 0.56 0.59 Polymer 19a 1.3 0.62Polymer 5 2.4 0.52 Polymer 19b 0.56 0.54 Polymer 19h 3.15 0.59¹Additional information regarding the calculation of the block indicesfor various polymers is disclosed in U.S. patent application Ser. No.11/376,835, entitled “Ethylene/α-Olefin Block Interpolymers”, filed onMar. 15, 2006, in the name of Colin L. P. Shan, Lonnie Hazlitt, et. al.and assigned to Dow Global Technologies Inc., the disclose of which isincorporated by reference herein ²Zn/C₂ * 1000 = (Zn feed flow * Znconcentration/1000000/Mw of Zn)/(Total Ethylene feed flow * (1 −fractional ethylene conversion rate)/Mw of Ethylene) * 1000. Please notethat “Zn” in “Zn/C₂ * 1000” refers to the amount of zinc in diethyl zinc(“DEZ”) used in the polymerization process, and “C2” refers to theamount of ethylene used in the polymerization process.

TABLE 10 Polymerization Conditions for Polymers 19k-l. Cat Cat Cat A1²A1 B2³ Cat B2 DEZ Cocat Cocat [Zn]⁴ Poly C₈H₁₆ Solv. H₂ T Conc. FlowConc. Flow DEZ Flow Conc. Flow in polymer Rate⁵ Conv.⁶ Polymer Ex. kg/hrkg/hr sccm¹ ° C. ppm kg/hr ppm kg/hr Conc % kg/hr ppm kg/hr ppm kg/hr wt% w % Eff.⁷ 19k 15.79 149.88 124 120 600 0.09 200 0.27 3 0.34 4500 0.24257 38.71 87.5 17.09 319 19l 10.08 174.57 82 120 600 0.42 200 0.28 30.39 4500 0.39 335 34.18 88.7 14.28 223 ¹standard cm³/min²[N-(2,6-di(1-methylethyl)phenyl)amido)(2-isopropylphenyl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafniumdimethyl³bis-(1-(2-methylcyclohexyl)ethyl)(2-oxoyl-3,5-di(t-butyl)phenyl)immino)zirconium dimethyl ⁴ppm in final product calculated by mass balance⁵polymer production rate ⁶weight percent ethylene conversion in reactor⁷efficiency, kg polymer/g M where g M = g Hf + g Z

Comparative Examples L-S and Examples 20-40

The foaming temperature disclosed herein, unless otherwise stated, isthe optimal gel temperature for foaming when the melt strength is highenough to stabilize the foam and prevent cell collapse.

The foaming window disclosed herein, unless otherwise stated, is thetemperature range of the polymer/blowing agent mixture exiting the diethat provides stable foam with the lowest density and open cell content.Above this temperature range, the foam is unstable and collapses andbelow this temperature range the polymer freezes and crystallizes out ofthe melt.

Comparative Example L was a foam prepared from a mixture of 100 parts byweight of LDPE 620i (a low density polyethylene from The Dow ChemicalCompany, Midland, Mich.), 10 parts by weight of isobutane, 1.5 parts byweight of HYDROCEROL® CF 20 (a nucleating agent from ClariantCorporation, Charlotte, N.C.), 0.2 parts by weight of IRGANOX™ 1010 (anantioxidant from Ciba Geigy, N.Y.) and 1 part by weight of gycerolmonostearate. The mixture was converted into a foam plank using a singlebarrier screw foaming line having a 40 lbs/hr (i.e., 18.1 Kg/hr)capacity. The 40 lb/hr extrusion line consisted of a 1.75 inches (i.e.,4.445 cm) single screw extruder (LID: 30:1) with a feeding zone forresins and solid additives, a melting zone, and a metering zone. Inaddition, there were a mixing zone with a port for injecting blowingagents and liquid additives and a cooling zone to uniformly cool themelt to the foaming temperature. The line also consisted of a gear pumpbetween the metering and mixing zones to stabilize the melt flow and astatic mixer in the cooling zone to improve gel temperature uniformity.The melt was extruded through a ½ inch (i.e., 1.27 cm) slit die toambient temperature and pressure. The melt or gel was allowed to expandto the desired shape. The residence time was 18 minutes. The foamingline was equipped with cooling front end to lower melt temperature to105-110° C. The ½ inch slit die was used to control the cross-section ofthe foam plank to about/½inch×3 inches (i.e., 1.27 cm×7.62 cm). Thefoaming range was between 106 and 112° C. The freeze-off was at 104-105°C. The foaming window was measured starting at about 112° C. and thefoaming temperature was reduced in 1° C. steps until the foam densityincreased. The density and open cell content of the extruded foam wererecorded in every 1° C. step.

Comparative Example M was a foam prepared similarly according to theprocedure for Comparative Example L except that 30 wt % of LDPE 620i wasreplaced with AFFINITY® 1880 (a polyolefin plastomer from The DowChemical Company, Midland, Mich.). Comparative Example N was a foamprepared similarly according to the procedure for Comparative Example Lexcept that 40 wt % of LDPE 620i was replaced with AFFINITY® 1880 (apolyolefin plastomer from The Dow Chemical Company, Midland, Mich.).Comparative Example O was a foam prepared similarly according to theprocedure for Comparative Example L except that 50 wt % of LDPE 620i wasreplaced with AFFINITY® 1880 (a polyolefin plastomer from The DowChemical Company, Midland, Mich.).

Example 20 was a foam prepared similarly according to the procedure forComparative Example 1 except that 30 wt % of LDPE 620i was replaced withExample 19k. Example 21 was a foam prepared similarly according to theprocedure for Comparative Example L except that 50 wt % of LDPE 620i wasreplaced with Example 19k. Example 22 was a foam prepared similarlyaccording to the procedure for Comparative Example L except that 70 wt %of LDPE 620i was replaced with Example 19k.

Example 23 was a foam prepared similarly according to the procedure forComparative Example L except that 30 wt % of LDPE 620i was replaced withExample 19a. Example 23P was a foam prepared similarly according to theprocedure for Example 23 except that LDPE 620i and Example 19a waspreblended. The polymer blend was compounded at 190° C. for 10 minuteson a Werner Pfleiderer ZSK-30 twin screw compounder (L/D 1:30) at 50lb/hr with a 10 min residence time. The extruded polymer strands werecooled under water and air dried and pelletized with a Conairpelletizer. Example 24 was a foam prepared similarly according to theprocedure for Comparative Example L except that 50 wt % of LDPE 620i wasreplaced with Example 19a. Example 25 was a foam prepared similarlyaccording to the procedure for Comparative Example L except that 70 wt %of LDPE 620i was replaced with Example 19a. Example 26 was a foamprepared similarly according to the procedure for Comparative Example Lexcept that 100 wt % of LDPE 620i was replaced with Example 19a.

Example 27 was a foam prepared similarly according to the procedure forComparative Example L except that 30 wt % of LDPE 620i was replaced withExample 19b. Example 28 was a foam prepared similarly according to theprocedure for Comparative Example L except that 50 wt % of LDPE 620i wasreplaced with Example 19b. Example 29 was a foam prepared similarlyaccording to the procedure for Comparative Example L except that 70 wt %of LDPE 620i was replaced with Example 19b.

Example 30 was a foam prepared similarly according to the procedure forComparative Example L except that 30 wt % of LDPE 620i was replaced withExample 19l. Example 31 was a foam prepared similarly according to theprocedure for Comparative Example L except that 50 wt % of LDPE 620i wasreplaced with Example 19l. Example 32 was a foam prepared similarlyaccording to the procedure for Comparative Example L except that 70 wt %of LDPE 620i was replaced with Example 19l. Example 33 was a foamprepared similarly according to the procedure for Comparative Example Lexcept that 100 wt % of LDPE 620i was replaced with Example 19l.

Comparative Example P was a foam prepared similarly according to theprocedure for Comparative Example L except that the chemical ingredientswere replaced with 100 parts by weight of PROFAX® PF 814 (a HMS PP fromMontell Polyolefins, Wilmington, Del.), 6 parts by weight of isobutane,0.5 parts by weight of talc, 0.5 parts by weight of IRGANOX™ 1010 (anantioxidant from Ciba Geigy, New York) and 0.5 part by weight of calciumstearate.

Example 34 was a foam prepared similarly according to the procedure forComparative Example P except that 30 wt % of PROFAX® PF 814 was replacedwith Example 19k. Example 35 was a foam prepared similarly according tothe procedure for Comparative Example P except that 50 wt % of PROFAX®PF 814 was replaced with Example 19k. Example 36 was a foam preparedsimilarly according to the procedure for Comparative Example P exceptthat 70 wt % of PROFAX® PF 814 was replaced with Example 19k. Example 37was a foam prepared similarly according to the procedure for ComparativeExample P except that 30 wt % of PROFAX® PF 814 was replaced withExample 19a. Example 38 was a foam prepared similarly according to theprocedure for Comparative Example P except that 50 wt % of PROFAX® PF814 was replaced with Example 19a. Example 39 was a foam preparedsimilarly according to the procedure for Comparative Example P exceptthat 30 wt % of PROFAX® PF 814 was replaced with Example 19a. Example 40was a foam prepared similarly according to the procedure for ComparativeExample P except that 50 wt % of PROFAX® PF 814 was replaced withExample 19a. Example 41 was a foam prepared similarly according to theprocedure for Comparative Example P except that 30 wt % of PROFAX® PF814 was replaced with Example 19l. Example 42 was a foam preparedsimilarly according to the procedure for Comparative Example P exceptthat 50 wt % of PROFAX® PF 814 was replaced with Example 19l.

Comparative Example Q was a foam prepared similarly according to theprocedure for Comparative Example P except that 30 wt % of PROFAX® PF814 was replaced with AFFINITY® 8100 (a polyolefin plastomer from TheDow Chemical Company, Midland, Mich.). Comparative Example R was a foamprepared similarly according to the procedure for Comparative Example Pexcept that 50 wt % of PROFAX® PF 814 was replaced with AFFINITY® 8100.Comparative Example S was a foam prepared similarly according to theprocedure for Comparative Example P except that 70 wt % of PROFAX® PF814 was replaced with AFFINITY® 8100. Comparative Example U was a foamprepared similarly according to the procedure for Comparative Example Pexcept that 30 wt % of PROFAX® PF 814 was replaced with VERSIFY® DE 2300(a propylene-ethylene copolymers from The Dow Chemical Company, Midland,Mich.). Comparative Example V was a foam prepared similarly according tothe procedure for Comparative Example P except that 50 wt % of PROFAX®PF 814 was replaced with VERSIFY® DE 2300.

Measurements of Foam Properties

The foam densities of Examples 20, 23, 23P, 30 and 31, and ComparativeExamples L and N were measured according to ASTM D3575-00 Suffix W,which is incorporated herein by reference. The foam densities of thefoam examples are shown in FIG. 8 and Table 13.

The percentages of open cell of Examples 20, 23, 23P, 30, 31, 34-35 and37-42 and Comparative Examples L, N, Q, R, U and V were measuredaccording to ASTM D2856-94 (1998), which is incorporated herein byreference. The percentages of open cell of the foam examples are shownin FIGS. 9 and 23 and Table 13.

The cell sizes of Examples 23, 23P and 30, and Comparative Examples Land M were measured according to FP-156, which is incorporated herein byreference. The cell sizes of the foam examples are shown in FIG. 10 andin Table 12.

The Asker C hardness of Examples 23, 23P and 30, and ComparativeExamples L and M were measured with an Asker Type C Style Durometeraccording to standard industry procedure. The Asker C hardness resultsof the foam examples are shown in FIG. 11.

The compression creep of Examples 23, 23P, 30, 34-35 and 37-42, andComparative Examples L, M, Q, R, U and V were measured according to ASTMD 3575-00 Suffix B, which is incorporated herein by reference. Thecompression creep results of the foam examples are shown in FIGS. 12 and20.

The compression deflection of Examples 23, 23P, 30, 34-35 and 37-42, andComparative Examples L, M, Q, R, U and V were measured according to ASTMD 3575-00 Suffix D, which is incorporated herein by reference. Thecompression deflection results of the foam examples are shown in FIGS.13 and 21. After the test, the compression recovery of Examples 34-35and 37-42, and Comparatives Examples Q, R, U and V were measured after 1hour, 1 day, 1 week, and up to 4 weeks. The compression recovery resultsof Examples 34-35 and 37-42, and Comparatives Examples Q, R, U and V areshown in FIG. 22.

The compression set of Examples 23, 23P, 30, 34-35 and 37-42, andComparative Examples L, M, Q, R, U and V were measured according to CIDA-A-59136 (1997), which is incorporated herein by reference. Thecompression set results of the foam examples are shown in FIGS. 17, 18,26 and 27.

The tensile strength and elongation of Examples 23, 23P, 30, 34-35 and37-42, and Comparative Examples L, M, Q, R, U and V were measuredaccording to ASTM D 412-98 per ASTM D3575 Suffix T, which isincorporated herein by reference. The tensile strength and elongationresults of the foam examples are shown in FIGS. 14 and 25.

The tear strength and elongation of Examples 23, 23P, 30, 34-35 and37-42, and Comparative Examples L, M, Q, R, U and V were measuredaccording to ASTM D 624-98 per ASTM D3575 Suffix G, which isincorporated herein by reference. The tear strength and elongationresults of the foam examples are shown in FIGS. 15 and 24.

The abrasion performances of Examples 23, 23P and 30, and ComparativeExamples L and M were measured using a Sutherland rub tester accordingto ASTM D 5264, which is incorporated herein by reference. The abrasionresults of the foam examples are shown in FIG. 16 and Table 12.

The sound absorption of Examples 23 and 30 and Comparative Examples Land M in the frequency range from 1600 to 6400 hz were measuredaccording to ASTM E1050, which is incorporated herein by reference. Thesound absorption data of the foam examples are shown in Table 11 andFIG. 19.

TABLE 11 The Sound Absorption Coefficients of Examples 23 and 30 andComparative Examples L and M and the Parameters and Conditions for theMeasurements. Measurement Lines 800 Span 6.4 kHz Averages 100 Zoom FALSECentre Frequency (Hz): 3200 Tube type Small Generator Generator ActiveTRUE Waveform: Random Signal Level: 0.500 Vrms Pink Filter: OffEnvironment Atmospheric Pressure: 1013.25 hPa Temperature: 72.00° F.Relative Humidity: 50.00% Velocity of Sound: 344.41 m/s Density of Air:1.194 kg/m³ Characteristic Impedance of Air: 411.2 Pa/(m/s) OptionsSignal-to-Noise Ratio below: 10.0 dB Autospectrum (Max-Min) above: 60.0dB Calibration Factor exceeds:  2.0 dB Calibration Factor exceeds: 2.0degrees Transfer Function Estimate: H1 Example 23 L M 30 f (HZ) RealPart Real Part Real Part Real Part 1632 6.66E−02 5.46E−02 7.01E−028.14E−02 1760 6.92E−02 5.63E−02 7.29E−02 8.54E−02 1888 7.38E−02 5.69E−027.61E−02 9.09E−02 2008 7.76E−02 5.87E−02 7.93E−02 9.67E−02 2136 8.41E−026.10E−02 8.28E−02 1.05E−01 2264 9.01E−02 6.42E−02 8.82E−02 1.16E−01 23929.89E−02 6.82E−02 9.32E−02 1.28E−01 2536 1.07E−01 7.19E−02 9.93E−021.43E−01 2664 1.17E−01 7.59E−02 1.06E−01 1.61E−01 2792 1.28E−01 8.02E−021.14E−01 1.83E−01 2920 1.37E−01 8.42E−02 1.21E−01 2.06E−01 3048 1.41E−018.07E−02 1.20E−01 2.26E−01 3176 1.51E−01 8.14E−02 1.24E−01 2.57E−01 33041.84E−01 1.04E−01 1.51E−01 3.08E−01 3432 2.00E−01 1.13E−01 1.64E−013.47E−01 3560 2.25E−01 1.27E−01 1.82E−01 3.93E−01 3688 2.52E−01 1.42E−012.03E−01 4.39E−01 3816 2.76E−01 1.51E−01 2.20E−01 4.77E−01 3944 3.09E−011.67E−01 2.47E−01 5.12E−01 4072 3.44E−01 1.83E−01 2.76E−01 5.33E−01 42003.77E−01 1.93E−01 3.06E−01 5.34E−01 4328 4.12E−01 2.08E−01 3.45E−015.21E−01 4456 4.51E−01 2.25E−01 3.91E−01 4.98E−01 4584 4.93E−01 2.46E−014.41E−01 4.67E−01 4704 5.33E−01 2.67E−01 4.83E−01 4.34E−01 4784 5.63E−012.82E−01 5.05E−01 4.19E−01 4848 5.86E−01 2.98E−01 5.21E−01 4.05E−01 49766.22E−01 3.28E−01 5.33E−01 3.78E−01 5040 6.36E−01 3.44E−01 5.32E−013.65E−01 5168 6.48E−01 3.79E−01 5.19E−01 3.46E−01 5232 6.40E−01 3.89E−015.06E−01 3.33E−01 5360 6.13E−01 4.09E−01 4.86E−01 3.12E−01 5424 5.93E−014.13E−01 4.75E−01 2.99E−01 5488 5.70E−01 4.18E−01 4.67E−01 2.91E−01 56165.20E−01 4.14E−01 4.43E−01 2.77E−01 5680 4.94E−01 4.06E−01 4.32E−012.71E−01 5744 4.71E−01 3.97E−01 4.17E−01 2.65E−01 5872 4.24E−01 3.75E−013.84E−01 2.56E−01 5936 4.03E−01 3.64E−01 3.65E−01 2.50E−01 6000 3.84E−013.51E−01 3.47E−01 2.45E−01 6128 3.52E−01 3.36E−01 3.16E−01 2.36E−01 61923.38E−01 3.33E−01 3.02E−01 2.33E−01 6256 3.24E−01 3.29E−01 2.89E−012.28E−01 6384 3.02E−01 3.32E−01 2.71E−01 2.23E−01

TABLE 12 The abrasion performances of Examples 23, 23P and 30 andComparative Examples L and M. Initial Final Gloss Initial Color GlossFinal Color Δ Gloss 20° 60° L* a* b* 20° 60° L* a* b* 20° 60° Example L84.2 89.4 23.68 −0.20 −0.66 79.4 88.4 23.56 −0.19 −0.62 −2.1 −0.6 83.489.0 82.4 88.8 82.3 89.2 81.8 88.7 Example M 79.0 87.6 23.67 −0.20−64.00 76.2 86.4 23.69 −0.23 −0.64 −2.0 −1.2 81.9 88.2 79.7 86.9 82.688.9 81.5 87.7 Example 23P 80.3 88.5 23.67 −0.20 −0.66 77.4 86.7 23.58−0.20 −0.59 −1.6 −1.0 @ 108 C. 82.7 88.4 80.7 87.2 83.0 88.9 83.0 88.8Example 23P 80.4 88.7 23.67 −0.22 −0.64 76.7 86.8 23.69 −0.22 −0.64 −1.0−0.8 @ 106 C. 80.4 89.1 80.8 88.7 82.7 89.2 82.9 89.0 Example 30 80.088.1 23.68 −0.25 −0.62 77.1 86.6 23.47 −0.19 −0.57 −1.7 −1.6 @ 110 C.81.1 88.0 80.9 86.6 81.7 88.3 79.8 86.4 Example 30 81.0 88.2 23.66 −0.23−0.66 79.8 87.1 23.47 −0.17 −0.60 −0.9 −0.1 @ 108 C. 83.3 87.5 82.2 87.983.1 87.6 82.7 88.0 Example 23 80.2 87.8 23.74 −0.23 −0.63 77.1 85.823.44 −16.00 −0.55 −2.1 −1.2 @ 109 C. 83.0 87.4 80.5 86.3 82.9 87.5 82.186.9 Example 23 81.2 88.1 23.68 −0.23 −0.65 79.7 86.9 23.46 −0.19 −0.56−1.9 −0.7 @ 107 C. 83.9 87.9 80.2 86.9 82.5 87.3 82.1 87.3 Δ Color Color20 Gloss 60 Gloss Av Gloss Cell size L a b Change Change ChangeRetention mm Example L −0.12 0.01 0.04 0.1269 0.9748 0.9936 0.9842 0.46Example M 0.02 −0.03 63.36 63.3600 0.9749 0.9860 0.9805 0.69 Example 23P−0.09 0.00 0.07 0.1140 0.9801 0.9883 0.9842 0.61 @ 108 C. Example 23P0.02 0.00 0.00 0.0200 0.9873 0.9906 0.9890 0.56 @ 106 C. Example 30−0.21 0.06 0.05 0.2241 0.9794 0.9818 0.9806 0.7 @ 110 C. Example 30−0.19 0.06 0.06 0.2081 0.9891 0.9989 0.9940 0.74 @ 108 C. Example 23−0.30 −15.77 0.08 15.7731 0.9740 0.9859 0.9800 0.84 @ 109 C. Example 23−0.22 0.04 0.09 0.2410 0.9774 0.9916 0.9845 0.73 @ 107 C.

TABLE 13 The foam densities and percentages of open cell of Examples 20,23, 23P, 30 and 31 and Comparative Examples L and N at foamingtemperatures range of 103-112° C. Example L Example N Example 20 Example30 Example 31 Example 23 Example 23P density open density open densityopen density open density open density open density open Temp, C. (pcf)cell (%) (pcf) cell (%) (pcf) cell (%) (pcf) cell (%) (pcf) cell (%)(pcf) cell (%) (pcf) cell (%) 112 1.78 20 preblend 111 1.87 21.4 1.9645.7 110 2.4 32 1.8 20.5 1.89 45.7 2.17 39 1.72 26.5 109 57.3 1.85 91.91 49.2 1.89 32.9 1.75 22.5 108 2.1 21 1.99 83.2 2.18 37.5 1.84 19.91.97 56.2 1.99 24.1 1.82 18.2 107 2.05 12 2.22 37.9 1.99 64.4 1.81 201.87 17.5 106 2.1 18 2.12 24.1 2.5 30.7 2.18 82.1 1.97 16.7 2 19.3 1052.2 17 2.05 20.5 2.63 30.7 1.84 60.9 2.04 20.4 104 2.2 23 1.91 13.1 2.6637.2 103 2.3 25 1.95 12 2.2

FIG. 19 indicates that Examples 23 and 30 have equal or higher soundabsorption coefficients that those of Comparative Examples M and L. Ingeneral, Examples 23, 23P, 30, 34-35 and 37-42 show higher linearchanges than Comparative Examples L, M, Q, R, U and V in the compressioncreep test (see FIGS. 12 and 20), whereas the compressive strengths ofExamples 23, 23P and 30 are about the same as those of ComparativeExamples L and M (See FIG. 13). Further, FIG. 16 indicates that theaverage gloss retentions of Example 23, Example 23P and Example 30 aregenerally higher than those of Comparative Examples L and M in theabrasion test.

While the invention has been described with respect to a limited numberof embodiments, the specific features of one embodiment should not beattributed to other embodiments of the invention. No single embodimentis representative of all aspects of the invention. In some embodiments,the compositions or methods may include numerous compounds or steps notmentioned herein. In other embodiments, the compositions or methods donot include, or are substantially free of, any compounds or steps notenumerated herein. Variations and modifications from the describedembodiments exist. Finally, any number disclosed herein should beconstrued to mean approximate, regardless of whether the word “about” or“approximately” is used in describing the number. The appended claimsintend to cover all those modifications and variations as falling withinthe scope of the invention.

1. A soft foam comprising at least one ethylene/α-olefin interpolymer, wherein the density of the soft foam is from about 10 to 150 kg/m³ and wherein the ethylene/α-olefin interpolymer is a block interpolymer and: (a) has a M_(w)/M_(n) from about 1.7 to about 3.5, at least one melting point, T_(m), in degrees Celsius, and a density, d, in grams/cubic centimeter, wherein the numerical values of T_(m) and d correspond to the relationship: T _(m)≧−2002.9+4538.5(d)−2422.2(d)²; or (b) has a M_(w)/M_(n) from about 1.7 to about 3.5, and is characterized by a heat of fusion, ΔH in J/g, and a delta quantity, ΔT, in degrees Celsius defined as the temperature difference between the tallest DSC peak and the tallest CRYSTAF peak, wherein the numerical values of ΔT and ΔH have the following relationships: ΔT>−0.1299(ΔH)+62.81 for ΔH greater than zero and up to 130 J/g, ΔT≧−48° C. for ΔH greater than 130 J/g,  wherein the CRYSTAF peak is determined using at least 5 percent of the cumulative polymer, and if less than 5 percent of the polymer has an identifiable CRYSTAF peak, then the CRYSTAF temperature is 30° C.; or (c) is characterized by an elastic recovery, Re, in percent at 300 percent strain and 1 cycle measured with a compression-molded film of the ethylene/α-olefin interpolymer, and has a density, d, in grams/cubic centimeter, wherein the numerical values of Re and d satisfy the following relationship when ethylene/α-olefin interpolymer is substantially free of a cross-linked phase: Re>1481−1629(d); or (d) has a molecular fraction which elutes between 40° C. and 130° C. when fractionated using TREF, characterized in that the fraction has a molar comonomer content of at least 5 percent higher than that of a comparable random ethylene interpolymer fraction eluting between the same temperatures, wherein said comparable random ethylene interpolymer has the same comonomer(s) and has a melt index, density, and molar comonomer content (based on the whole polymer) within 10 percent of that of the ethylene/α-olefin interpolymer; or (e) has a storage modulus at 25° C., G′(25° C.), and a storage modulus at 100° C., G′(100° C.), wherein the ratio of G′(25° C.) to G′(100° C.) is in the range of about 1:1 to about 9:1.
 2. The soft foam of claim 1, wherein the ethylene/α-olefin interpolymer has a M_(w)/M_(n) from about 1.7 to about 3.5, at least one melting point, T_(m) , in degrees Celsius, and a density, d, in grams/cubic centimeter, wherein the numerical values of T_(m) and d correspond to the relationship: T _(m)≧858.91−1825.3(d)+1112.8(d)².
 3. The soft foam of claim 1, wherein the ethylene/α-olefin interpolymer has a M_(w)/M_(n) from about 1.7 to about 3.5 and is characterized by a heat of fusion, ΔH in J/g, and a delta quantity, ΔT, in degrees Celsius defined as the temperature difference between the tallest DSC peak and the tallest CRYSTAF peak, wherein the numerical values of ΔT and ΔH have the following relationships: ΔT>−0.1299(ΔH)+62.81 for ΔH greater than zero and up to 130 J/g, ΔT≧48° C. for ΔH greater than 130 J/g, wherein the CRYSTAF peak is determined using at least 5 percent of the cumulative polymer, and if less than 5 percent of the polymer has an identifiable CRYSTAF peak, then the CRYSTAF temperature is 30° C.
 4. The soft foam of claim 1, wherein the ethylene/α-olefin interpolymer is characterized by an elastic recovery, Re, in percent at 300 percent strain and 1 cycle measured with a compression-molded film of the ethylene/α-olefin interpolymer, and has a density, d, in grams/cubic centimeter, wherein the numerical values of Re and d satisfy the following relationship when ethylene/α-olefin interpolymer is substantially free of a cross-linked phase: Re>1481−1629(d).
 5. The soft foam of claim 1, wherein the numerical values of Re and d satisfy the following relationship: Re>1491−1629(d).
 6. The soft foam of claim 1, wherein the numerical values of Re and d satisfy the following relationship: Re>1501−1629(d).
 7. The soft foam of claim 1, wherein the numerical values of Re and d satisfy the following relationship: Re>1511−1629(d).
 8. The soft foam of claim 1, wherein the ethylene/α-olefin interpolymer has a molecular fraction which elutes between 40° C. and 130° C. when fractionated using TREF, characterized in that the fraction has a molar comonomer content of at least 5 percent higher than that of a comparable random ethylene interpolymer fraction eluting between the same temperatures, wherein said comparable random ethylene interpolymer has the same comonomer(s) and has a melt index, density, and molar comonomer content (based on the whole polymer) within 10 percent of that of the ethylene/α-olefin interpolymer.
 9. The soft foam of claim 1, wherein the ethylene/α-olefin interpolymer has a storage modulus at 25° C., G′(25° C.), and a storage modulus at 100° C.,G′(100° C.), wherein the ratio of G′(25° C.) to G′(100° C.) is in the range of about 1:1 to about 9:1.
 10. The soft foam of claim 1, wherein the α-olefin in the ethylene/α-olefin interpolymer is styrene, propylene, 1-butene, 1-hexene, 1-octene, 4-methyl-1-pentene, norbornene, 1-decene, 1,5-hexadiene, or a combination thereof.
 11. The soft foam of claim 1, wherein the soft foam contains less than 5 wt. % of gel per ASTM D-2765-84 Method A.
 12. The soft foam of claim 1 further comprising a polyolefin.
 13. The soft foam of claim 12, the polyolefin is a low density polyethylene, a high-melt-strength polypropylene or a combination thereof.
 14. The soft foam of claim 12, wherein the ratio of the polyolefin to the ethylene/α-olefin interpolymer is from about 1:10 to about 10:1 by weight.
 15. The soft foam of claim 1 further comprising at least an additive, wherein the additive is a grafting initiator, cross-linking catalyst, blowing agent activator, coagent, plasticizer, colorant or pigment, stability control agent, nucleating agent, filler, antioxidant, acid scavenger, ultraviolet stabilizer, flame retardant, lubricant, processing aid, extrusion aid or a combination thereof.
 16. A soft foam comprising at least one ethylene/α-olefin interpolymer, wherein the density of the soft foam is from about 10 to 150 kg/m³ and wherein the ethylene/α-olefin interpolymer is a block interpolymer and has: (a) at least one molecular fraction which elutes between 40° C. and 130° C. when fractionated using TREF, characterized in that the fraction has a block index of at least 0.5 and up to about 1 and a molecular weight distribution, M_(w)/M_(n), greater than about 1.3; or (b) an average block index greater than zero and up to about 1.0 and a molecular weight distribution, M_(w)/M_(n) greater than about 1.3.
 17. The soft foam of claim 16, wherein the ethylene/α-olefin interpolymer has at least one molecular fraction which elutes between 40° C. and 130° C. when fractionated using TREF, characterized in that the fraction has a block index of at least 0.5 and up to about 1 and a molecular weight distribution, M_(w)/M_(n), greater than about 1.3.
 18. The soft foam of claim 16, wherein the ethylene/α-olefin interpolymer has an average block index greater than zero and up to about 1.0 and a molecular weight distribution, M_(w)/M_(n), greater than about 1.3.
 19. The soft foam of claim 16, wherein the α-olefin the ethylene/α-olefin interpolymer is styrene, propylene, 1-butene, 1-hexene, 1-octene, 4-methyl-1-pentene, norbornene, 1-decene, 1,5-hexadiene, or a combination thereof.
 20. The soft foam of claim 16, wherein the soft foam contains less than 5 wt.% of gel per ASTM D-2765-84 Method A.
 21. The soft foam of claim 16 further comprising a polyolefin.
 22. The soft foam of claim 21, the polyolefin is a low density polyethylene, a high-melt-strength polypropylene or a combination thereof.
 23. The soft foam of claim 21, wherein the ratio of the polyolefin to the ethylene/α-olefin interpolymer is from about 1:10 to about 10:1 by weight.
 24. The soft foam of claim 16 further comprising at least an additive, wherein the additive is a grafting initiator, cross-linking catalyst, blowing agent activator, coagent, plasticizer, colorant or pigment, stability control agent, nucleating agent, filler, antioxidant, acid scavenger, ultraviolet stabilizer, flame retardant, lubricant, processing aid, extrusion aid or a combination thereof.
 25. A foamable composition comprising: (i) a blowing agent; and (ii) at least one ethylene/α-olefin interpolymer, wherein the ethylene/α-olefin interpolymer is a block interpolymer and: (a) has a M_(w)/M_(n) from about 1.7 to about 3.5, at least one melting point, T_(m), in degrees Celsius, and a density, d, in grams/cubic centimeter, wherein the numerical values of T_(m) and d correspond to the relationship: T _(m)≧−2002.9+4538.5(d)−2422.2(d)²; or (b) has a M_(w)/M_(n) from about 1.7 to about 3.5, and is characterized by a heat of fusion, ΔH in J/g, and a delta quantity, ΔT, in degrees Celsius defined as the temperature difference between the tallest DSC peak and the tallest CRYSTAF peak, wherein the numerical values of ΔT and ΔH have the following relationships: ΔT>−0.1299(ΔH)+62.81 for ΔH greater than zero and up to 130 J/g, ΔT≧48° C. for ΔH greater than 130 J/g,  wherein the CRYSTAF peak is determined using at least 5 percent of the cumulative polymer, and if less than 5 percent of the polymer has an identifiable CRYSTAF peak, then the CRYSTAF temperature is 30° C.; or (c) is characterized by an elastic recovery, Re, in percent at 300 percent strain and 1 cycle measured with a compression-molded film of the ethylene/α-olefin interpolymer, and has a density, d, in grams/cubic centimeter, wherein the numerical values of Re and d satisfy the following relationship when the ethylene/α-olefin interpolymer is substantially free of a cross-linked phase: Re>1481−1629(d); or (d) has a molecular fraction which elutes between 40° C. and 130° C. when fractionated using TREF, characterized in that the fraction has a molar comonomer content of at least 5 percent higher than that of a comparable random ethylene interpolymer fraction eluting between the same temperatures, wherein said comparable random ethylene interpolymer has the same comonomer(s) and has a melt index, density, and molar comonomer content (based on the whole polymer) within 10 percent of that of the ethylene/α-olefin interpolymer; or (e) has a storage modulus at 25° C., G′(25° C.), and a storage modulus at 100° C., G′(100° C.), wherein the ratio of G′(25° C.) to G′(100° C.) is in the range of about 1:1 to about 9:1.
 26. The foamable composition of claim 25, wherein the blowing agent is isobutane.
 27. The foamable composition of claim 25 further comprising at least an additive, wherein the additive is a grafting initiator, cross-linking catalyst, blowing agent activator, coagent, plasticizer, colorant or pigment, stability control agent, nucleating agent, filler, antioxidant, acid scavenger, ultraviolet stabilizer, flame retardant, lubricant, processing aid, extrusion aid or a combination thereof.
 28. The foamable composition of claim 25 further comprising a polyolefin.
 29. The foamable composition of claim 28, wherein the polyolefin is a low density polyethylene, a high-melt-strength polypropylene or a combination thereof.
 30. A foamable composition comprising: (i) a blowing agent; and (ii) at least one ethylene/α-olefin interpolymer, wherein the ethylene/α-olefin interpolymer is a block interpolymer and has: (a) at least one molecular fraction which elutes between 40° C. and 130° C. when fractionated using TREF, characterized in that the fraction has a block index of at least 0.5 and up to about 1 and a molecular weight distribution, M_(w)/M_(n), greater than about 1.3; or (b) an average block index greater than zero and up to about 1.0 and a molecular weight distribution, M_(w)/M_(n), greater than about 1.3.
 31. The foamable composition of claim 30, wherein the blowing agent is isobutane.
 32. The foamable composition of claim 30 further comprising at least an additive, wherein the additive is a grafting initiator, cross-linking catalyst, blowing agent activator, coagent, plasticizer, colorant or pigment, stability control agent, nucleating agent, filler, antioxidant, acid scavenger, ultraviolet stabilizer, flame retardant, lubricant, processing aid, extrusion aid or a combination thereof.
 33. The foamable composition of claim 30 further comprising a polyolefin.
 34. The foamable composition of claim 33, wherein the polyolefin is a low density polyethylene, a high-melt-strength polypropylene or a combination thereof.
 35. A foam article comprising the soft foam of claim
 1. 36. The foam article of claim 35, wherein the foam article is suitable for acoustical insulation, vibration control, cushioning, specialty packaging, automotive soft touch, thermal insulation or impact absorption.
 37. A foam article comprising the soft foam of claim
 16. 38. The foam article of claim 37, wherein the foam article is suitable for acoustical insulation, vibration control, cushioning, specialty packaging, automotive soft touch, thermal insulation or impact absorption. 